diff --git a/debuggerd/Android.bp b/debuggerd/Android.bp
index f0131b8..6dc6675 100644
--- a/debuggerd/Android.bp
+++ b/debuggerd/Android.bp
@@ -1,25 +1,197 @@
+cc_defaults {
+    name: "debuggerd_defaults",
+    cflags: [
+        "-Wall",
+        "-Wextra",
+        "-Wno-error",
+        "-Wno-nullability-completeness",
+        "-Os",
+    ],
+
+    local_include_dirs: ["include"],
+}
+
 cc_library_static {
-  name: "libdebuggerd_client",
-  srcs: ["client/debuggerd_client.cpp"],
+    name: "libdebuggerd_handler",
+    defaults: ["debuggerd_defaults"],
+    srcs: ["handler/debuggerd_handler.cpp"],
 
-  cflags: [
-    "-Wall",
-    "-Wextra",
-    "-Werror",
-    "-Os",
-  ],
+    // libdebuggerd_handler gets async signal safe logging via libc_logging,
+    // which defines its interface in bionic private headers.
+    include_dirs: ["bionic/libc"],
+    static_libs: ["libc_logging"],
 
-  target: {
-    android64: {
-      cflags: ["-DTARGET_IS_64_BIT"],
+    export_include_dirs: ["include"],
+}
+
+cc_library {
+    name: "libdebuggerd_client",
+    defaults: ["debuggerd_defaults"],
+    srcs: [
+        "client/debuggerd_client.cpp",
+        "util.cpp",
+    ],
+
+    shared_libs: [
+        "libbase",
+        "libcutils",
+    ],
+    export_include_dirs: ["include"],
+}
+
+cc_library {
+    name: "libdebuggerd",
+    defaults: ["debuggerd_defaults"],
+
+    srcs: [
+        "libdebuggerd/backtrace.cpp",
+        "libdebuggerd/elf_utils.cpp",
+        "libdebuggerd/open_files_list.cpp",
+        "libdebuggerd/tombstone.cpp",
+        "libdebuggerd/utility.cpp",
+    ],
+
+    target: {
+        android_arm: {
+            srcs: ["libdebuggerd/arm/machine.cpp"],
+        },
+        android_arm64: {
+            srcs: ["libdebuggerd/arm64/machine.cpp"],
+        },
+        android_mips: {
+            srcs: ["libdebuggerd/mips/machine.cpp"],
+        },
+        android_mips64: {
+            srcs: ["libdebuggerd/mips64/machine.cpp"],
+        },
+        android_x86: {
+            srcs: ["libdebuggerd/x86/machine.cpp"],
+        },
+        android_x86_64: {
+            srcs: ["libdebuggerd/x86_64/machine.cpp"],
+        },
     },
-  },
 
-  local_include_dirs: ["include"],
-  export_include_dirs: ["include"],
+    local_include_dirs: ["libdebuggerd/include"],
+    export_include_dirs: ["libdebuggerd/include"],
 
-  // libdebuggerd_client gets async signal safe logging via libc_logging,
-  // which defines its interface in bionic private headers.
-  include_dirs: ["bionic/libc"],
-  static_libs: ["libc_logging"],
+    shared_libs: [
+        "libbacktrace",
+        "libbase",
+        "libcutils",
+        "liblog",
+    ],
+}
+
+cc_test {
+    name: "debuggerd_test",
+    defaults: ["debuggerd_defaults"],
+
+    cflags: ["-Wno-missing-field-initializers"],
+    srcs: [
+        "libdebuggerd/test/dump_memory_test.cpp",
+        "libdebuggerd/test/elf_fake.cpp",
+        "libdebuggerd/test/log_fake.cpp",
+        "libdebuggerd/test/open_files_list_test.cpp",
+        "libdebuggerd/test/property_fake.cpp",
+        "libdebuggerd/test/ptrace_fake.cpp",
+        "libdebuggerd/test/tombstone_test.cpp",
+    ],
+
+    target: {
+        android: {
+            srcs: [
+                "debuggerd_test.cpp",
+                "util.cpp"
+            ],
+        },
+    },
+
+    shared_libs: [
+        "libbacktrace",
+        "libbase",
+        "libcutils",
+    ],
+
+    static_libs: [
+        "libdebuggerd"
+    ],
+
+    local_include_dirs: [
+        "libdebuggerd",
+    ],
+
+    compile_multilib: "both",
+    multilib: {
+        lib32: {
+            stem: "debuggerd_test32",
+        },
+        lib64: {
+            stem: "debuggerd_test64",
+        },
+    },
+}
+
+cc_binary {
+    name: "crash_dump",
+    srcs: [
+        "crash_dump.cpp",
+        "util.cpp",
+    ],
+    defaults: ["debuggerd_defaults"],
+
+    compile_multilib: "both",
+    multilib: {
+        lib32: {
+            suffix: "32",
+        },
+        lib64: {
+            suffix: "64",
+        },
+    },
+
+    shared_libs: [
+        "libbacktrace",
+        "libbase",
+        "libdebuggerd",
+        "liblog",
+        "libprocinfo",
+        "libselinux",
+    ],
+}
+
+cc_binary {
+    name: "debuggerd",
+    srcs: [
+        "debuggerd.cpp",
+    ],
+    defaults: ["debuggerd_defaults"],
+
+    shared_libs: [
+        "libbase",
+        "libdebuggerd_client",
+        "liblog",
+        "libselinux",
+    ],
+
+    local_include_dirs: ["include"],
+}
+
+cc_binary {
+    name: "tombstoned",
+    srcs: [
+        "util.cpp",
+        "tombstoned/intercept_manager.cpp",
+        "tombstoned/tombstoned.cpp",
+    ],
+    defaults: ["debuggerd_defaults"],
+
+    static_libs: [
+        "libbase",
+        "libcutils",
+        "libevent",
+        "liblog",
+    ],
+
+    init_rc: ["tombstoned/tombstoned.rc"]
 }
diff --git a/debuggerd/Android.mk b/debuggerd/Android.mk
deleted file mode 100644
index e3bdd43..0000000
--- a/debuggerd/Android.mk
+++ /dev/null
@@ -1,167 +0,0 @@
-LOCAL_PATH := $(call my-dir)
-
-common_cppflags := \
-    -W \
-    -Wall \
-    -Wextra \
-    -Wunused \
-    -Werror \
-
-ifeq ($(TARGET_IS_64_BIT),true)
-common_cppflags += -DTARGET_IS_64_BIT
-endif
-
-include $(CLEAR_VARS)
-
-LOCAL_SRC_FILES:= \
-    backtrace.cpp \
-    debuggerd.cpp \
-    elf_utils.cpp \
-    getevent.cpp \
-    open_files_list.cpp \
-    signal_sender.cpp \
-    tombstone.cpp \
-    utility.cpp \
-
-LOCAL_SRC_FILES_arm    := arm/machine.cpp
-LOCAL_SRC_FILES_arm64  := arm64/machine.cpp
-LOCAL_SRC_FILES_mips   := mips/machine.cpp
-LOCAL_SRC_FILES_mips64 := mips64/machine.cpp
-LOCAL_SRC_FILES_x86    := x86/machine.cpp
-LOCAL_SRC_FILES_x86_64 := x86_64/machine.cpp
-
-LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
-LOCAL_CPPFLAGS := $(common_cppflags)
-
-LOCAL_INIT_RC_32 := debuggerd.rc
-LOCAL_INIT_RC_64 := debuggerd64.rc
-
-LOCAL_SHARED_LIBRARIES := \
-    libbacktrace \
-    libbase \
-    libcutils \
-    liblog \
-    libselinux \
-
-LOCAL_CLANG := true
-
-LOCAL_MODULE := debuggerd
-LOCAL_MODULE_STEM_32 := debuggerd
-LOCAL_MODULE_STEM_64 := debuggerd64
-LOCAL_MULTILIB := both
-
-include $(BUILD_EXECUTABLE)
-
-crasher_cppflags := $(common_cppflags) -O0 -fstack-protector-all -Wno-free-nonheap-object
-
-include $(CLEAR_VARS)
-LOCAL_SRC_FILES := crasher.cpp
-LOCAL_SRC_FILES_arm    := arm/crashglue.S
-LOCAL_SRC_FILES_arm64  := arm64/crashglue.S
-LOCAL_SRC_FILES_mips   := mips/crashglue.S
-LOCAL_SRC_FILES_mips64 := mips64/crashglue.S
-LOCAL_SRC_FILES_x86    := x86/crashglue.S
-LOCAL_SRC_FILES_x86_64 := x86_64/crashglue.S
-LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
-LOCAL_MODULE_TAGS := optional
-LOCAL_CPPFLAGS := $(crasher_cppflags)
-LOCAL_SHARED_LIBRARIES := libbase liblog
-
-# The arm emulator has VFP but not VFPv3-D32.
-ifeq ($(ARCH_ARM_HAVE_VFP_D32),true)
-LOCAL_ASFLAGS_arm += -DHAS_VFP_D32
-endif
-
-LOCAL_MODULE := crasher
-LOCAL_MODULE_STEM_32 := crasher
-LOCAL_MODULE_STEM_64 := crasher64
-LOCAL_MULTILIB := both
-
-include $(BUILD_EXECUTABLE)
-
-include $(CLEAR_VARS)
-LOCAL_SRC_FILES := crasher.cpp
-LOCAL_SRC_FILES_arm    := arm/crashglue.S
-LOCAL_SRC_FILES_arm64  := arm64/crashglue.S
-LOCAL_SRC_FILES_mips   := mips/crashglue.S
-LOCAL_SRC_FILES_mips64 := mips64/crashglue.S
-LOCAL_SRC_FILES_x86    := x86/crashglue.S
-LOCAL_SRC_FILES_x86_64 := x86_64/crashglue.S
-LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
-LOCAL_MODULE_TAGS := optional
-LOCAL_CPPFLAGS := $(crasher_cppflags) -DSTATIC_CRASHER
-LOCAL_FORCE_STATIC_EXECUTABLE := true
-
-# The arm emulator has VFP but not VFPv3-D32.
-ifeq ($(ARCH_ARM_HAVE_VFP_D32),true)
-LOCAL_ASFLAGS_arm += -DHAS_VFP_D32
-endif
-
-LOCAL_MODULE := static_crasher
-LOCAL_MODULE_STEM_32 := static_crasher
-LOCAL_MODULE_STEM_64 := static_crasher64
-LOCAL_MULTILIB := both
-
-LOCAL_STATIC_LIBRARIES := libdebuggerd_client libbase liblog
-
-include $(BUILD_EXECUTABLE)
-
-debuggerd_test_src_files := \
-    utility.cpp \
-    open_files_list.cpp \
-    test/dump_memory_test.cpp \
-    test/elf_fake.cpp \
-    test/log_fake.cpp \
-    test/open_files_list_test.cpp \
-    test/property_fake.cpp \
-    test/ptrace_fake.cpp \
-    test/tombstone_test.cpp \
-    test/selinux_fake.cpp \
-
-debuggerd_shared_libraries := \
-    libbacktrace \
-    libbase \
-    libcutils \
-    liblog
-
-debuggerd_c_includes := \
-    $(LOCAL_PATH)/test \
-
-debuggerd_cpp_flags := \
-    $(common_cppflags) \
-    -Wno-missing-field-initializers \
-    -fno-rtti \
-
-# Bug: http://b/29823425 Disable -Wvarargs for Clang update to r271374
-debuggerd_cpp_flags += -Wno-varargs
-
-# Only build the host tests on linux.
-ifeq ($(HOST_OS),linux)
-
-include $(CLEAR_VARS)
-
-LOCAL_MODULE := debuggerd_test
-LOCAL_SRC_FILES := $(debuggerd_test_src_files)
-LOCAL_SHARED_LIBRARIES := $(debuggerd_shared_libraries)
-LOCAL_C_INCLUDES := $(debuggerd_c_includes)
-LOCAL_CPPFLAGS := $(debuggerd_cpp_flags)
-
-LOCAL_MODULE_STEM_32 := $(LOCAL_MODULE)32
-LOCAL_MODULE_STEM_64 := $(LOCAL_MODULE)64
-LOCAL_MULTILIB := both
-include $(BUILD_HOST_NATIVE_TEST)
-
-endif
-
-include $(CLEAR_VARS)
-
-LOCAL_MODULE := debuggerd_test
-LOCAL_SRC_FILES := $(debuggerd_test_src_files)
-LOCAL_SHARED_LIBRARIES := $(debuggerd_shared_libraries)
-LOCAL_C_INCLUDES := $(debuggerd_c_includes)
-LOCAL_CPPFLAGS := $(debuggerd_cpp_flags)
-
-LOCAL_MODULE_STEM_32 := $(LOCAL_MODULE)32
-LOCAL_MODULE_STEM_64 := $(LOCAL_MODULE)64
-LOCAL_MULTILIB := both
-include $(BUILD_NATIVE_TEST)
diff --git a/debuggerd/client/debuggerd_client.cpp b/debuggerd/client/debuggerd_client.cpp
index c67d747..81d70df 100644
--- a/debuggerd/client/debuggerd_client.cpp
+++ b/debuggerd/client/debuggerd_client.cpp
@@ -1,379 +1,189 @@
 /*
- * Copyright (C) 2008 The Android Open Source Project
- * All rights reserved.
+ * Copyright 2016, The Android Open Source Project
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *  * Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- *  * Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in
- *    the documentation and/or other materials provided with the
- *    distribution.
+ * 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
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
- * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
- * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
- * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
+ *     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 "debuggerd/client.h"
+#include <debuggerd/client.h>
 
-#include <errno.h>
-#include <inttypes.h>
-#include <pthread.h>
-#include <sched.h>
+#include <fcntl.h>
 #include <signal.h>
-#include <stddef.h>
-#include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
-#include <sys/mman.h>
-#include <sys/prctl.h>
-#include <sys/socket.h>
-#include <sys/syscall.h>
-#include <sys/un.h>
-#include <sys/wait.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 #include <unistd.h>
 
-#include "private/libc_logging.h"
+#include <chrono>
 
-#if defined(TARGET_IS_64_BIT) && !defined(__LP64__)
-#define SOCKET_NAME "android:debuggerd32"
-#else
-#define SOCKET_NAME "android:debuggerd"
-#endif
+#include <android-base/logging.h>
+#include <android-base/stringprintf.h>
+#include <android-base/unique_fd.h>
+#include <cutils/sockets.h>
+#include <debuggerd/handler.h>
+#include <debuggerd/protocol.h>
+#include <debuggerd/util.h>
 
-// see man(2) prctl, specifically the section about PR_GET_NAME
-#define MAX_TASK_NAME_LEN (16)
+using android::base::unique_fd;
 
-static debuggerd_callbacks_t g_callbacks;
-
-// Don't use __libc_fatal because it exits via abort, which might put us back into a signal handler.
-#define fatal(...)                                             \
-  do {                                                         \
-    __libc_format_log(ANDROID_LOG_FATAL, "libc", __VA_ARGS__); \
-    _exit(1);                                                  \
-  } while (0)
-
-static int socket_abstract_client(const char* name, int type) {
-  sockaddr_un addr;
-
-  // Test with length +1 for the *initial* '\0'.
-  size_t namelen = strlen(name);
-  if ((namelen + 1) > sizeof(addr.sun_path)) {
-    errno = EINVAL;
-    return -1;
-  }
-
-  // This is used for abstract socket namespace, we need
-  // an initial '\0' at the start of the Unix socket path.
-  //
-  // Note: The path in this case is *not* supposed to be
-  // '\0'-terminated. ("man 7 unix" for the gory details.)
-  memset(&addr, 0, sizeof(addr));
-  addr.sun_family = AF_LOCAL;
-  addr.sun_path[0] = 0;
-  memcpy(addr.sun_path + 1, name, namelen);
-
-  socklen_t alen = namelen + offsetof(sockaddr_un, sun_path) + 1;
-
-  int s = socket(AF_LOCAL, type, 0);
-  if (s == -1) {
-    return -1;
-  }
-
-  int rc = TEMP_FAILURE_RETRY(connect(s, reinterpret_cast<sockaddr*>(&addr), alen));
-  if (rc == -1) {
-    close(s);
-    return -1;
-  }
-
-  return s;
-}
-
-/*
- * Writes a summary of the signal to the log file.  We do this so that, if
- * for some reason we're not able to contact debuggerd, there is still some
- * indication of the failure in the log.
- *
- * We could be here as a result of native heap corruption, or while a
- * mutex is being held, so we don't want to use any libc functions that
- * could allocate memory or hold a lock.
- */
-static void log_signal_summary(int signum, const siginfo_t* info) {
-  const char* signal_name = "???";
-  bool has_address = false;
-  switch (signum) {
-    case SIGABRT:
-      signal_name = "SIGABRT";
-      break;
-    case SIGBUS:
-      signal_name = "SIGBUS";
-      has_address = true;
-      break;
-    case SIGFPE:
-      signal_name = "SIGFPE";
-      has_address = true;
-      break;
-    case SIGILL:
-      signal_name = "SIGILL";
-      has_address = true;
-      break;
-    case SIGSEGV:
-      signal_name = "SIGSEGV";
-      has_address = true;
-      break;
-#if defined(SIGSTKFLT)
-    case SIGSTKFLT:
-      signal_name = "SIGSTKFLT";
-      break;
-#endif
-    case SIGSYS:
-      signal_name = "SIGSYS";
-      break;
-    case SIGTRAP:
-      signal_name = "SIGTRAP";
-      break;
-  }
-
-  char thread_name[MAX_TASK_NAME_LEN + 1];  // one more for termination
-  if (prctl(PR_GET_NAME, reinterpret_cast<unsigned long>(thread_name), 0, 0, 0) != 0) {
-    strcpy(thread_name, "<name unknown>");
-  } else {
-    // short names are null terminated by prctl, but the man page
-    // implies that 16 byte names are not.
-    thread_name[MAX_TASK_NAME_LEN] = 0;
-  }
-
-  // "info" will be null if the siginfo_t information was not available.
-  // Many signals don't have an address or a code.
-  char code_desc[32];  // ", code -6"
-  char addr_desc[32];  // ", fault addr 0x1234"
-  addr_desc[0] = code_desc[0] = 0;
-  if (info != nullptr) {
-    // For a rethrown signal, this si_code will be right and the one debuggerd shows will
-    // always be SI_TKILL.
-    __libc_format_buffer(code_desc, sizeof(code_desc), ", code %d", info->si_code);
-    if (has_address) {
-      __libc_format_buffer(addr_desc, sizeof(addr_desc), ", fault addr %p", info->si_addr);
-    }
-  }
-  __libc_format_log(ANDROID_LOG_FATAL, "libc", "Fatal signal %d (%s)%s%s in tid %d (%s)", signum,
-                    signal_name, code_desc, addr_desc, gettid(), thread_name);
-}
-
-/*
- * Returns true if the handler for signal "signum" has SA_SIGINFO set.
- */
-static bool have_siginfo(int signum) {
-  struct sigaction old_action, new_action;
-
-  memset(&new_action, 0, sizeof(new_action));
-  new_action.sa_handler = SIG_DFL;
-  new_action.sa_flags = SA_RESTART;
-  sigemptyset(&new_action.sa_mask);
-
-  if (sigaction(signum, &new_action, &old_action) < 0) {
-    __libc_format_log(ANDROID_LOG_WARN, "libc", "Failed testing for SA_SIGINFO: %s",
-                      strerror(errno));
+static bool send_signal(pid_t pid, bool backtrace) {
+  sigval val;
+  val.sival_int = backtrace;
+  if (sigqueue(pid, DEBUGGER_SIGNAL, val) != 0) {
+    PLOG(ERROR) << "libdebuggerd_client: failed to send signal to pid " << pid;
     return false;
   }
-  bool result = (old_action.sa_flags & SA_SIGINFO) != 0;
-
-  if (sigaction(signum, &old_action, nullptr) == -1) {
-    __libc_format_log(ANDROID_LOG_WARN, "libc", "Restore failed in test for SA_SIGINFO: %s",
-                      strerror(errno));
-  }
-  return result;
+  return true;
 }
 
-static void send_debuggerd_packet(pid_t crashing_tid, pid_t pseudothread_tid) {
-  // Mutex to prevent multiple crashing threads from trying to talk
-  // to debuggerd at the same time.
-  static pthread_mutex_t crash_mutex = PTHREAD_MUTEX_INITIALIZER;
-  int ret = pthread_mutex_trylock(&crash_mutex);
-  if (ret != 0) {
-    if (ret == EBUSY) {
-      __libc_format_log(ANDROID_LOG_INFO, "libc",
-                        "Another thread contacted debuggerd first; not contacting debuggerd.");
-      // This will never complete since the lock is never released.
-      pthread_mutex_lock(&crash_mutex);
-    } else {
-      __libc_format_log(ANDROID_LOG_INFO, "libc", "pthread_mutex_trylock failed: %s", strerror(ret));
+static bool check_dumpable(pid_t pid) {
+  // /proc/<pid> is owned by the effective UID of the process.
+  // Ownership of most of the other files in /proc/<pid> varies based on PR_SET_DUMPABLE.
+  // If PR_GET_DUMPABLE would return 0, they're owned by root, instead.
+  std::string proc_pid_path = android::base::StringPrintf("/proc/%d/", pid);
+  std::string proc_pid_status_path = proc_pid_path + "/status";
+
+  unique_fd proc_pid_fd(open(proc_pid_path.c_str(), O_DIRECTORY | O_RDONLY | O_CLOEXEC));
+  if (proc_pid_fd == -1) {
+    return false;
+  }
+  unique_fd proc_pid_status_fd(openat(proc_pid_fd, "status", O_RDONLY | O_CLOEXEC));
+  if (proc_pid_status_fd == -1) {
+    return false;
+  }
+
+  struct stat proc_pid_st;
+  struct stat proc_pid_status_st;
+  if (fstat(proc_pid_fd.get(), &proc_pid_st) != 0 ||
+      fstat(proc_pid_status_fd.get(), &proc_pid_status_st) != 0) {
+    return false;
+  }
+
+  // We can't figure out if a process is dumpable if its effective UID is root, but that's fine
+  // because being root bypasses the PR_SET_DUMPABLE check for ptrace.
+  if (proc_pid_st.st_uid == 0) {
+    return true;
+  }
+
+  if (proc_pid_status_st.st_uid == 0) {
+    return false;
+  }
+
+  return true;
+}
+
+bool debuggerd_trigger_dump(pid_t pid, unique_fd output_fd, DebuggerdDumpType dump_type,
+                            int timeout_ms) {
+  LOG(INFO) << "libdebuggerd_client: started dumping process " << pid;
+  unique_fd sockfd;
+  const auto end = std::chrono::steady_clock::now() + std::chrono::milliseconds(timeout_ms);
+  auto set_timeout = [timeout_ms, &sockfd, &end]() {
+    if (timeout_ms <= 0) {
+      return true;
     }
-    return;
-  }
 
-  int s = socket_abstract_client(SOCKET_NAME, SOCK_STREAM | SOCK_CLOEXEC);
-  if (s == -1) {
-    __libc_format_log(ANDROID_LOG_FATAL, "libc", "Unable to open connection to debuggerd: %s",
-                      strerror(errno));
-    return;
-  }
-
-  // debuggerd knows our pid from the credentials on the
-  // local socket but we need to tell it the tid of the crashing thread.
-  // debuggerd will be paranoid and verify that we sent a tid
-  // that's actually in our process.
-  debugger_msg_t msg;
-  msg.action = DEBUGGER_ACTION_CRASH;
-  msg.tid = crashing_tid;
-  msg.ignore_tid = pseudothread_tid;
-  msg.abort_msg_address = 0;
-
-  if (g_callbacks.get_abort_message) {
-    msg.abort_msg_address = reinterpret_cast<uintptr_t>(g_callbacks.get_abort_message());
-  }
-
-  ret = TEMP_FAILURE_RETRY(write(s, &msg, sizeof(msg)));
-  if (ret == sizeof(msg)) {
-    char debuggerd_ack;
-    ret = TEMP_FAILURE_RETRY(read(s, &debuggerd_ack, 1));
-    if (g_callbacks.post_dump) {
-      g_callbacks.post_dump();
+    auto now = std::chrono::steady_clock::now();
+    if (now > end) {
+      return false;
     }
-  } else {
-    // read or write failed -- broken connection?
-    __libc_format_log(ANDROID_LOG_FATAL, "libc", "Failed while talking to debuggerd: %s",
-                      strerror(errno));
-  }
 
-  close(s);
-}
+    auto time_left = std::chrono::duration_cast<std::chrono::microseconds>(end - now);
+    auto seconds = std::chrono::duration_cast<std::chrono::seconds>(time_left);
+    auto microseconds = std::chrono::duration_cast<std::chrono::microseconds>(time_left - seconds);
+    struct timeval timeout = {
+      .tv_sec = static_cast<long>(seconds.count()),
+      .tv_usec = static_cast<long>(microseconds.count()),
+    };
 
-struct debugger_thread_info {
-  pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
-  pid_t crashing_tid;
-  pid_t pseudothread_tid;
-  int signal_number;
-  siginfo_t* info;
-};
+    if (setsockopt(sockfd, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof(timeout)) != 0) {
+      return false;
+    }
+    if (setsockopt(sockfd, SOL_SOCKET, SO_SNDTIMEO, &timeout, sizeof(timeout)) != 0) {
+      return false;
+    }
 
-// Logging and contacting debuggerd requires free file descriptors, which we might not have.
-// Work around this by spawning a "thread" that shares its parent's address space, but not its file
-// descriptor table, so that we can close random file descriptors without affecting the original
-// process. Note that this doesn't go through pthread_create, so TLS is shared with the spawning
-// process.
-static void* pseudothread_stack;
-static int debuggerd_dispatch_pseudothread(void* arg) {
-  debugger_thread_info* thread_info = static_cast<debugger_thread_info*>(arg);
-
-  for (int i = 3; i < 1024; ++i) {
-    close(i);
-  }
-
-  log_signal_summary(thread_info->signal_number, thread_info->info);
-  send_debuggerd_packet(thread_info->crashing_tid, thread_info->pseudothread_tid);
-  pthread_mutex_unlock(&thread_info->mutex);
-  return 0;
-}
-
-/*
- * Catches fatal signals so we can ask debuggerd to ptrace us before
- * we crash.
- */
-static void debuggerd_signal_handler(int signal_number, siginfo_t* info, void*) {
-  // It's possible somebody cleared the SA_SIGINFO flag, which would mean
-  // our "info" arg holds an undefined value.
-  if (!have_siginfo(signal_number)) {
-    info = nullptr;
-  }
-
-  debugger_thread_info thread_info = {
-    .crashing_tid = gettid(),
-    .signal_number = signal_number,
-    .info = info
+    return true;
   };
 
-  pthread_mutex_lock(&thread_info.mutex);
-  pid_t child_pid = clone(debuggerd_dispatch_pseudothread, pseudothread_stack,
-                          CLONE_THREAD | CLONE_SIGHAND | CLONE_VM | CLONE_CHILD_SETTID,
-                          &thread_info, nullptr, nullptr, &thread_info.pseudothread_tid);
-
-  if (child_pid == -1) {
-    fatal("failed to spawn debuggerd dispatch thread: %s", strerror(errno));
+  if (!check_dumpable(pid)) {
+    dprintf(output_fd.get(), "target pid %d is not dumpable\n", pid);
+    return true;
   }
 
-  // Wait for the child to finish and unlock the mutex.
-  // This relies on bionic behavior that isn't guaranteed by the standard.
-  pthread_mutex_lock(&thread_info.mutex);
-
-
-  // We need to return from the signal handler so that debuggerd can dump the
-  // thread that crashed, but returning here does not guarantee that the signal
-  // will be thrown again, even for SIGSEGV and friends, since the signal could
-  // have been sent manually. Resend the signal with rt_tgsigqueueinfo(2) to
-  // preserve the SA_SIGINFO contents.
-  signal(signal_number, SIG_DFL);
-
-  struct siginfo si;
-  if (!info) {
-    memset(&si, 0, sizeof(si));
-    si.si_code = SI_USER;
-    si.si_pid = getpid();
-    si.si_uid = getuid();
-    info = &si;
-  } else if (info->si_code >= 0 || info->si_code == SI_TKILL) {
-    // rt_tgsigqueueinfo(2)'s documentation appears to be incorrect on kernels
-    // that contain commit 66dd34a (3.9+). The manpage claims to only allow
-    // negative si_code values that are not SI_TKILL, but 66dd34a changed the
-    // check to allow all si_code values in calls coming from inside the house.
+  sockfd.reset(socket(AF_LOCAL, SOCK_SEQPACKET, 0));
+  if (sockfd == -1) {
+    PLOG(ERROR) << "libdebugger_client: failed to create socket";
+    return false;
   }
 
-  int rc = syscall(SYS_rt_tgsigqueueinfo, getpid(), gettid(), signal_number, info);
-  if (rc != 0) {
-    fatal("failed to resend signal during crash: %s", strerror(errno));
+  if (!set_timeout()) {
+    PLOG(ERROR) << "libdebugger_client: failed to set timeout";
+    return false;
   }
+
+  if (socket_local_client_connect(sockfd.get(), kTombstonedInterceptSocketName,
+                                  ANDROID_SOCKET_NAMESPACE_RESERVED, SOCK_SEQPACKET) == -1) {
+    PLOG(ERROR) << "libdebuggerd_client: failed to connect to tombstoned";
+    return false;
+  }
+
+  InterceptRequest req = {.pid = pid };
+  if (!set_timeout()) {
+    PLOG(ERROR) << "libdebugger_client: failed to set timeout";
+  }
+
+  if (send_fd(sockfd.get(), &req, sizeof(req), std::move(output_fd)) != sizeof(req)) {
+    PLOG(ERROR) << "libdebuggerd_client: failed to send output fd to tombstoned";
+    return false;
+  }
+
+  bool backtrace = dump_type == kDebuggerdBacktrace;
+  send_signal(pid, backtrace);
+
+  if (!set_timeout()) {
+    PLOG(ERROR) << "libdebugger_client: failed to set timeout";
+  }
+
+  InterceptResponse response;
+  ssize_t rc = TEMP_FAILURE_RETRY(recv(sockfd.get(), &response, sizeof(response), MSG_TRUNC));
+  if (rc == 0) {
+    LOG(ERROR) << "libdebuggerd_client: failed to read response from tombstoned: timeout reached?";
+    return false;
+  } else if (rc != sizeof(response)) {
+    LOG(ERROR)
+      << "libdebuggerd_client: received packet of unexpected length from tombstoned: expected "
+      << sizeof(response) << ", received " << rc;
+    return false;
+  }
+
+  if (response.success != 1) {
+    response.error_message[sizeof(response.error_message) - 1] = '\0';
+    LOG(ERROR) << "libdebuggerd_client: tombstoned reported failure: " << response.error_message;
+  }
+
+  LOG(INFO) << "libdebuggerd_client: done dumping process " << pid;
+
+  return true;
 }
 
-void debuggerd_init(debuggerd_callbacks_t* callbacks) {
-  if (callbacks) {
-    g_callbacks = *callbacks;
+int dump_backtrace_to_file(pid_t tid, int fd) {
+  return dump_backtrace_to_file_timeout(tid, fd, 0);
+}
+
+int dump_backtrace_to_file_timeout(pid_t tid, int fd, int timeout_secs) {
+  android::base::unique_fd copy(dup(fd));
+  if (copy == -1) {
+    return -1;
   }
-
-  void* thread_stack_allocation =
-    mmap(nullptr, PAGE_SIZE * 3, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
-  if (thread_stack_allocation == MAP_FAILED) {
-    fatal("failed to allocate debuggerd thread stack");
-  }
-
-  char* stack = static_cast<char*>(thread_stack_allocation) + PAGE_SIZE;
-  if (mprotect(stack, PAGE_SIZE, PROT_READ | PROT_WRITE) != 0) {
-    fatal("failed to mprotect debuggerd thread stack");
-  }
-
-  // Stack grows negatively, set it to the last byte in the page...
-  stack = (stack + PAGE_SIZE - 1);
-  // and align it.
-  stack -= 15;
-  pseudothread_stack = stack;
-
-  struct sigaction action;
-  memset(&action, 0, sizeof(action));
-  sigemptyset(&action.sa_mask);
-  action.sa_sigaction = debuggerd_signal_handler;
-  action.sa_flags = SA_RESTART | SA_SIGINFO;
-
-  // Use the alternate signal stack if available so we can catch stack overflows.
-  action.sa_flags |= SA_ONSTACK;
-
-  sigaction(SIGABRT, &action, nullptr);
-  sigaction(SIGBUS, &action, nullptr);
-  sigaction(SIGFPE, &action, nullptr);
-  sigaction(SIGILL, &action, nullptr);
-  sigaction(SIGSEGV, &action, nullptr);
-#if defined(SIGSTKFLT)
-  sigaction(SIGSTKFLT, &action, nullptr);
-#endif
-  sigaction(SIGTRAP, &action, nullptr);
+  int timeout_ms = timeout_secs > 0 ? timeout_secs * 1000 : 0;
+  return debuggerd_trigger_dump(tid, std::move(copy), kDebuggerdBacktrace, timeout_ms) ? 0 : -1;
 }
diff --git a/debuggerd/crash_dump.cpp b/debuggerd/crash_dump.cpp
new file mode 100644
index 0000000..b9dfedb
--- /dev/null
+++ b/debuggerd/crash_dump.cpp
@@ -0,0 +1,388 @@
+/*
+ * 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 <syscall.h>
+#include <sys/ptrace.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+#include <limits>
+#include <memory>
+#include <set>
+#include <vector>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/parseint.h>
+#include <android-base/properties.h>
+#include <android-base/stringprintf.h>
+#include <android-base/unique_fd.h>
+#include <cutils/sockets.h>
+#include <log/logger.h>
+#include <procinfo/process.h>
+#include <selinux/selinux.h>
+
+#include "backtrace.h"
+#include "tombstone.h"
+#include "utility.h"
+
+#include "debuggerd/handler.h"
+#include "debuggerd/protocol.h"
+#include "debuggerd/util.h"
+
+using android::base::unique_fd;
+using android::base::StringPrintf;
+
+static bool pid_contains_tid(pid_t pid, pid_t tid) {
+  std::string task_path = StringPrintf("/proc/%d/task/%d", pid, tid);
+  return access(task_path.c_str(), F_OK) == 0;
+}
+
+// Attach to a thread, and verify that it's still a member of the given process
+static bool ptrace_attach_thread(pid_t pid, pid_t tid) {
+  if (ptrace(PTRACE_ATTACH, tid, 0, 0) != 0) {
+    return false;
+  }
+
+  // Make sure that the task we attached to is actually part of the pid we're dumping.
+  if (!pid_contains_tid(pid, tid)) {
+    if (ptrace(PTRACE_DETACH, tid, 0, 0) != 0) {
+      PLOG(FATAL) << "failed to detach from thread " << tid;
+    }
+    errno = ECHILD;
+    return false;
+  }
+  return true;
+}
+
+static bool activity_manager_notify(int pid, int signal, const std::string& amfd_data) {
+  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,
+    .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;  // 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: binary 32-bit network-byte-order ints for the
+  // pid and signal number, followed by the raw text of the dump, culminating
+  // in a zero byte that marks end-of-data.
+  uint32_t datum = htonl(pid);
+  if (!android::base::WriteFully(amfd, &datum, 4)) {
+    PLOG(ERROR) << "AM pid write failed";
+    return false;
+  }
+  datum = htonl(signal);
+  if (!android::base::WriteFully(amfd, &datum, 4)) {
+    PLOG(ERROR) << "AM signal 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;
+}
+
+static bool tombstoned_connect(pid_t pid, unique_fd* tombstoned_socket, unique_fd* output_fd) {
+  unique_fd sockfd(socket_local_client(kTombstonedCrashSocketName,
+                                       ANDROID_SOCKET_NAMESPACE_RESERVED, SOCK_SEQPACKET));
+  if (sockfd == -1) {
+    PLOG(ERROR) << "failed to connect to tombstoned";
+    return false;
+  }
+
+  TombstonedCrashPacket packet = {};
+  packet.packet_type = CrashPacketType::kDumpRequest;
+  packet.packet.dump_request.pid = pid;
+  if (TEMP_FAILURE_RETRY(write(sockfd, &packet, sizeof(packet))) != sizeof(packet)) {
+    PLOG(ERROR) << "failed to write DumpRequest packet";
+    return false;
+  }
+
+  unique_fd tmp_output_fd;
+  ssize_t rc = recv_fd(sockfd, &packet, sizeof(packet), &tmp_output_fd);
+  if (rc == -1) {
+    PLOG(ERROR) << "failed to read response to DumpRequest packet";
+    return false;
+  } else if (rc != sizeof(packet)) {
+    LOG(ERROR) << "read DumpRequest response packet of incorrect length (expected "
+               << sizeof(packet) << ", got " << rc << ")";
+    return false;
+  }
+
+  *tombstoned_socket = std::move(sockfd);
+  *output_fd = std::move(tmp_output_fd);
+  return true;
+}
+
+static bool tombstoned_notify_completion(int tombstoned_socket) {
+  TombstonedCrashPacket packet = {};
+  packet.packet_type = CrashPacketType::kCompletedDump;
+  if (TEMP_FAILURE_RETRY(write(tombstoned_socket, &packet, sizeof(packet))) != sizeof(packet)) {
+    return false;
+  }
+  return true;
+}
+
+static void abort_handler(pid_t target, const bool& tombstoned_connected,
+                          unique_fd& tombstoned_socket, unique_fd& output_fd,
+                          const char* abort_msg) {
+  LOG(ERROR) << abort_msg;
+
+  // If we abort before we get an output fd, contact tombstoned to let any
+  // potential listeners know that we failed.
+  if (!tombstoned_connected) {
+    if (!tombstoned_connect(target, &tombstoned_socket, &output_fd)) {
+      // We failed to connect, not much we can do.
+      LOG(ERROR) << "failed to connected to tombstoned to report failure";
+      _exit(1);
+    }
+  }
+
+  dprintf(output_fd.get(), "crash_dump failed to dump process %d: %s\n", target, abort_msg);
+
+  // Don't dump ourselves.
+  _exit(1);
+}
+
+static void check_process(int proc_fd, pid_t expected_pid) {
+  android::procinfo::ProcessInfo proc_info;
+  if (!android::procinfo::GetProcessInfoFromProcPidFd(proc_fd, &proc_info)) {
+    LOG(FATAL) << "failed to fetch process info";
+  }
+
+  if (proc_info.pid != expected_pid) {
+    LOG(FATAL) << "pid mismatch: expected " << expected_pid << ", actual " << proc_info.ppid;
+  }
+}
+
+int main(int argc, char** argv) {
+  pid_t target = getppid();
+  bool tombstoned_connected = false;
+  unique_fd tombstoned_socket;
+  unique_fd output_fd;
+
+  android::base::InitLogging(argv);
+  android::base::SetAborter([&](const char* abort_msg) {
+    abort_handler(target, tombstoned_connected, tombstoned_socket, output_fd, abort_msg);
+  });
+
+  if (argc != 2) {
+    return 1;
+  }
+
+  pid_t main_tid;
+
+  if (target == 1) {
+    LOG(FATAL) << "target died before we could attach";
+  }
+
+  if (!android::base::ParseInt(argv[1], &main_tid, 1, std::numeric_limits<pid_t>::max())) {
+    LOG(FATAL) << "invalid main tid: " << argv[1];
+  }
+
+  android::procinfo::ProcessInfo target_info;
+  if (!android::procinfo::GetProcessInfo(main_tid, &target_info)) {
+    LOG(FATAL) << "failed to fetch process info for target " << main_tid;
+  }
+
+  if (main_tid != target_info.tid || target != target_info.pid) {
+    LOG(FATAL) << "target info mismatch, expected pid " << target << ", tid " << main_tid
+               << ", received pid " << target_info.pid << ", tid " << target_info.tid;
+  }
+
+  // Open /proc/`getppid()` in the original process, and pass it down to the forked child.
+  std::string target_proc_path = "/proc/" + std::to_string(target);
+  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;
+  }
+
+  // Reparent ourselves to init, so that the signal handler can waitpid on the
+  // original process to avoid leaving a zombie for non-fatal dumps.
+  pid_t forkpid = fork();
+  if (forkpid == -1) {
+    PLOG(FATAL) << "fork failed";
+  } else if (forkpid != 0) {
+    exit(0);
+  }
+
+  check_process(target_proc_fd, target);
+
+  int attach_error = 0;
+  if (!ptrace_attach_thread(target, main_tid)) {
+    PLOG(FATAL) << "failed to attach to thread " << main_tid << " in process " << target;
+  }
+
+  check_process(target_proc_fd, target);
+
+  LOG(INFO) << "obtaining output fd from tombstoned";
+  tombstoned_connected = tombstoned_connect(target, &tombstoned_socket, &output_fd);
+
+  // Write a '\1' to stdout to tell the crashing process to resume.
+  if (TEMP_FAILURE_RETRY(write(STDOUT_FILENO, "\1", 1)) == -1) {
+    PLOG(ERROR) << "failed to communicate to target process";
+  }
+
+  if (tombstoned_connected) {
+    if (TEMP_FAILURE_RETRY(dup2(output_fd.get(), STDOUT_FILENO)) == -1) {
+      PLOG(ERROR) << "failed to dup2 output fd (" << 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));
+  }
+
+  if (attach_error != 0) {
+    PLOG(FATAL) << "failed to attach to thread " << main_tid << " in process " << target;
+  }
+
+  LOG(INFO) << "performing dump of process " << target << " (target tid = " << main_tid << ")";
+
+  // At this point, the thread that made the request has been PTRACE_ATTACHed
+  // and has the signal that triggered things queued. Send PTRACE_CONT, and
+  // then wait for the signal.
+  if (ptrace(PTRACE_CONT, main_tid, 0, 0) != 0) {
+    PLOG(ERROR) << "PTRACE_CONT(" << main_tid << ") failed";
+    exit(1);
+  }
+
+  siginfo_t siginfo = {};
+  if (!wait_for_signal(main_tid, &siginfo)) {
+    printf("failed to wait for signal in tid %d: %s\n", main_tid, strerror(errno));
+    exit(1);
+  }
+
+  int signo = siginfo.si_signo;
+  bool backtrace = false;
+  uintptr_t abort_address = 0;
+
+  // si_value can represent three things:
+  //   0: dump tombstone
+  //   1: dump backtrace
+  //   everything else: abort message address (implies dump tombstone)
+  if (siginfo.si_value.sival_int == 1) {
+    backtrace = true;
+  } else if (siginfo.si_value.sival_ptr != nullptr) {
+    abort_address = reinterpret_cast<uintptr_t>(siginfo.si_value.sival_ptr);
+  }
+
+  // Now that we have the signal that kicked things off, attach all of the
+  // sibling threads, and then proceed.
+  bool fatal_signal = signo != DEBUGGER_SIGNAL;
+  int resume_signal = fatal_signal ? signo : 0;
+  std::set<pid_t> siblings;
+  if (resume_signal == 0) {
+    if (!android::procinfo::GetProcessTids(target, &siblings)) {
+      PLOG(FATAL) << "failed to get process siblings";
+    }
+    siblings.erase(main_tid);
+
+    for (pid_t sibling_tid : siblings) {
+      if (!ptrace_attach_thread(target, sibling_tid)) {
+        PLOG(FATAL) << "failed to attach to thread " << main_tid << " in process " << target;
+      }
+    }
+  }
+
+  check_process(target_proc_fd, target);
+
+  // TODO: Use seccomp to lock ourselves down.
+
+  std::unique_ptr<BacktraceMap> backtrace_map(BacktraceMap::Create(main_tid));
+  std::string amfd_data;
+
+  if (backtrace) {
+    dump_backtrace(output_fd.get(), backtrace_map.get(), target, main_tid, siblings, 0);
+  } else {
+    // Collect the list of open files.
+    OpenFilesList open_files;
+    populate_open_files_list(target, &open_files);
+
+    engrave_tombstone(output_fd.get(), backtrace_map.get(), open_files, target, main_tid, siblings,
+                      abort_address, fatal_signal ? &amfd_data : nullptr);
+  }
+
+  bool wait_for_gdb = android::base::GetBoolProperty("debug.debuggerd.wait_for_gdb", false);
+  if (wait_for_gdb) {
+    // Don't wait_for_gdb when the process didn't actually crash.
+    if (!fatal_signal) {
+      wait_for_gdb = false;
+    } else {
+      // Use ALOGI to line up with output from engrave_tombstone.
+      ALOGI(
+        "***********************************************************\n"
+        "* Process %d has been suspended while crashing.\n"
+        "* To attach gdbserver and start gdb, run this on the host:\n"
+        "*\n"
+        "*     gdbclient.py -p %d\n"
+        "*\n"
+        "***********************************************************",
+        target, main_tid);
+    }
+  }
+
+  for (pid_t tid : siblings) {
+    // Don't send the signal to sibling threads.
+    if (ptrace(PTRACE_DETACH, tid, 0, wait_for_gdb ? SIGSTOP : 0) != 0) {
+      PLOG(ERROR) << "ptrace detach from " << tid << " failed";
+    }
+  }
+
+  if (ptrace(PTRACE_DETACH, main_tid, 0, wait_for_gdb ? SIGSTOP : resume_signal)) {
+    PLOG(ERROR) << "ptrace detach from main thread " << main_tid << " failed";
+  }
+
+  if (wait_for_gdb) {
+    if (tgkill(target, main_tid, resume_signal) != 0) {
+      PLOG(ERROR) << "failed to resend signal to process " << target;
+    }
+  }
+
+  if (fatal_signal) {
+    activity_manager_notify(target, signo, amfd_data);
+  }
+
+  // Close stdout before we notify tombstoned of completion.
+  close(STDOUT_FILENO);
+  if (!tombstoned_notify_completion(tombstoned_socket.get())) {
+    LOG(ERROR) << "failed to notify tombstoned of completion";
+  }
+
+  return 0;
+}
diff --git a/debuggerd/crasher/Android.mk b/debuggerd/crasher/Android.mk
new file mode 100644
index 0000000..b8b786b
--- /dev/null
+++ b/debuggerd/crasher/Android.mk
@@ -0,0 +1,66 @@
+LOCAL_PATH := $(call my-dir)
+
+crasher_cppflags := \
+    -std=gnu++14 \
+    -W \
+    -Wall \
+    -Wextra \
+    -Wunused \
+    -Werror \
+    -O0 \
+    -fstack-protector-all \
+    -Wno-free-nonheap-object \
+    -Wno-date-time
+
+include $(CLEAR_VARS)
+LOCAL_SRC_FILES := crasher.cpp
+LOCAL_SRC_FILES_arm    := arm/crashglue.S
+LOCAL_SRC_FILES_arm64  := arm64/crashglue.S
+LOCAL_SRC_FILES_mips   := mips/crashglue.S
+LOCAL_SRC_FILES_mips64 := mips64/crashglue.S
+LOCAL_SRC_FILES_x86    := x86/crashglue.S
+LOCAL_SRC_FILES_x86_64 := x86_64/crashglue.S
+LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
+LOCAL_MODULE_TAGS := optional
+LOCAL_CPPFLAGS := $(crasher_cppflags)
+LOCAL_SHARED_LIBRARIES := libbase liblog
+
+# The arm emulator has VFP but not VFPv3-D32.
+ifeq ($(ARCH_ARM_HAVE_VFP_D32),true)
+LOCAL_ASFLAGS_arm += -DHAS_VFP_D32
+endif
+
+LOCAL_MODULE := crasher
+LOCAL_MODULE_STEM_32 := crasher
+LOCAL_MODULE_STEM_64 := crasher64
+LOCAL_MULTILIB := both
+
+include $(BUILD_EXECUTABLE)
+
+include $(CLEAR_VARS)
+LOCAL_SRC_FILES := crasher.cpp
+LOCAL_SRC_FILES_arm    := arm/crashglue.S
+LOCAL_SRC_FILES_arm64  := arm64/crashglue.S
+LOCAL_SRC_FILES_mips   := mips/crashglue.S
+LOCAL_SRC_FILES_mips64 := mips64/crashglue.S
+LOCAL_SRC_FILES_x86    := x86/crashglue.S
+LOCAL_SRC_FILES_x86_64 := x86_64/crashglue.S
+LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
+LOCAL_MODULE_TAGS := optional
+LOCAL_CPPFLAGS := $(crasher_cppflags) -DSTATIC_CRASHER
+LOCAL_FORCE_STATIC_EXECUTABLE := true
+LOCAL_SHARED_LIBRARIES := libbase liblog
+
+# The arm emulator has VFP but not VFPv3-D32.
+ifeq ($(ARCH_ARM_HAVE_VFP_D32),true)
+LOCAL_ASFLAGS_arm += -DHAS_VFP_D32
+endif
+
+LOCAL_MODULE := static_crasher
+LOCAL_MODULE_STEM_32 := static_crasher
+LOCAL_MODULE_STEM_64 := static_crasher64
+LOCAL_MULTILIB := both
+
+LOCAL_STATIC_LIBRARIES := libdebuggerd_handler libbase liblog
+
+include $(BUILD_EXECUTABLE)
diff --git a/debuggerd/arm/crashglue.S b/debuggerd/crasher/arm/crashglue.S
similarity index 100%
rename from debuggerd/arm/crashglue.S
rename to debuggerd/crasher/arm/crashglue.S
diff --git a/debuggerd/arm64/crashglue.S b/debuggerd/crasher/arm64/crashglue.S
similarity index 100%
rename from debuggerd/arm64/crashglue.S
rename to debuggerd/crasher/arm64/crashglue.S
diff --git a/debuggerd/crasher.cpp b/debuggerd/crasher/crasher.cpp
similarity index 99%
rename from debuggerd/crasher.cpp
rename to debuggerd/crasher/crasher.cpp
index 689f4d4..288f116 100644
--- a/debuggerd/crasher.cpp
+++ b/debuggerd/crasher/crasher.cpp
@@ -33,7 +33,7 @@
 #include <log/log.h>
 
 #if defined(STATIC_CRASHER)
-#include "debuggerd/client.h"
+#include "debuggerd/handler.h"
 #endif
 
 #define noinline __attribute__((__noinline__))
diff --git a/debuggerd/mips/crashglue.S b/debuggerd/crasher/mips/crashglue.S
similarity index 100%
rename from debuggerd/mips/crashglue.S
rename to debuggerd/crasher/mips/crashglue.S
diff --git a/debuggerd/mips64/crashglue.S b/debuggerd/crasher/mips64/crashglue.S
similarity index 100%
rename from debuggerd/mips64/crashglue.S
rename to debuggerd/crasher/mips64/crashglue.S
diff --git a/debuggerd/x86/crashglue.S b/debuggerd/crasher/x86/crashglue.S
similarity index 100%
rename from debuggerd/x86/crashglue.S
rename to debuggerd/crasher/x86/crashglue.S
diff --git a/debuggerd/x86_64/crashglue.S b/debuggerd/crasher/x86_64/crashglue.S
similarity index 100%
rename from debuggerd/x86_64/crashglue.S
rename to debuggerd/crasher/x86_64/crashglue.S
diff --git a/debuggerd/debuggerd.cpp b/debuggerd/debuggerd.cpp
index 893adc8..3208230 100644
--- a/debuggerd/debuggerd.cpp
+++ b/debuggerd/debuggerd.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright 2006, The Android Open Source Project
+ * 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.
@@ -14,937 +14,68 @@
  * limitations under the License.
  */
 
-#define LOG_TAG "debuggerd"
-
-#include <arpa/inet.h>
-#include <dirent.h>
-#include <elf.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <linux/input.h>
-#include <pthread.h>
-#include <signal.h>
-#include <stdarg.h>
+#include <err.h>
 #include <stdio.h>
-#include <sys/poll.h>
-#include <sys/prctl.h>
-#include <sys/ptrace.h>
-#include <sys/socket.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <sys/un.h>
-#include <time.h>
+#include <stdlib.h>
+#include <string.h>
 
-#include <memory>
-#include <set>
-#include <string>
-
-#include <selinux/android.h>
+#include <limits>
+#include <thread>
 
 #include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/parseint.h>
 #include <android-base/unique_fd.h>
-#include <cutils/debugger.h>
-#include <cutils/properties.h>
-#include <cutils/sockets.h>
-#include <log/log.h>
-
-#include <private/android_filesystem_config.h>
-
 #include <debuggerd/client.h>
+#include <debuggerd/util.h>
+#include <selinux/selinux.h>
 
-#include "backtrace.h"
-#include "getevent.h"
-#include "open_files_list.h"
-#include "signal_sender.h"
-#include "tombstone.h"
-#include "utility.h"
+using android::base::unique_fd;
 
-// If the 32 bit executable is compiled on a 64 bit system,
-// use the 32 bit socket name.
-#if defined(TARGET_IS_64_BIT) && !defined(__LP64__)
-#define SOCKET_NAME DEBUGGER32_SOCKET_NAME
-#else
-#define SOCKET_NAME DEBUGGER_SOCKET_NAME
-#endif
+static void usage(int exit_code) {
+  fprintf(stderr, "usage: debuggerd [-b] PID\n");
+  _exit(exit_code);
+}
 
-struct debugger_request_t {
-  debugger_action_t action;
-  pid_t pid, tid;
-  uid_t uid, gid;
-  pid_t ignore_tid;
-  uintptr_t abort_msg_address;
-};
+static std::thread spawn_redirect_thread(unique_fd fd) {
+  return std::thread([fd{ std::move(fd) }]() {
+    while (true) {
+      char buf[BUFSIZ];
+      ssize_t rc = TEMP_FAILURE_RETRY(read(fd.get(), buf, sizeof(buf)));
+      if (rc <= 0) {
+        return;
+      }
 
-static void wait_for_user_action(const debugger_request_t& request) {
-  // Explain how to attach the debugger.
-  ALOGI("***********************************************************\n"
-        "* Process %d has been suspended while crashing.\n"
-        "* To attach gdbserver and start gdb, run this on the host:\n"
-        "*\n"
-        "*     gdbclient.py -p %d\n"
-        "*\n"
-        "* Wait for gdb to start, then press the VOLUME DOWN key\n"
-        "* to let the process continue crashing.\n"
-        "***********************************************************",
-        request.pid, request.tid);
-
-  // Wait for VOLUME DOWN.
-  while (true) {
-    input_event e;
-    if (get_event(&e, -1) == 0) {
-      if (e.type == EV_KEY && e.code == KEY_VOLUMEDOWN && e.value == 0) {
-        break;
+      if (!android::base::WriteFully(STDOUT_FILENO, buf, rc)) {
+        return;
       }
     }
-  }
-
-  ALOGI("debuggerd resuming process %d", request.pid);
+  });
 }
 
-static int get_process_info(pid_t tid, pid_t* out_pid, uid_t* out_uid, uid_t* out_gid) {
-  char path[64];
-  snprintf(path, sizeof(path), "/proc/%d/status", tid);
+int main(int argc, char* argv[]) {
+  if (argc <= 1) usage(0);
+  if (argc > 3) usage(1);
+  if (argc == 3 && strcmp(argv[1], "-b") != 0) usage(1);
 
-  FILE* fp = fopen(path, "r");
-  if (!fp) {
-    return -1;
+  pid_t pid;
+  if (!android::base::ParseInt(argv[argc - 1], &pid, 1, std::numeric_limits<pid_t>::max())) {
+    usage(1);
   }
 
-  int fields = 0;
-  char line[1024];
-  while (fgets(line, sizeof(line), fp)) {
-    size_t len = strlen(line);
-    if (len > 6 && !memcmp(line, "Tgid:\t", 6)) {
-      *out_pid = atoi(line + 6);
-      fields |= 1;
-    } else if (len > 5 && !memcmp(line, "Uid:\t", 5)) {
-      *out_uid = atoi(line + 5);
-      fields |= 2;
-    } else if (len > 5 && !memcmp(line, "Gid:\t", 5)) {
-      *out_gid = atoi(line + 5);
-      fields |= 4;
-    }
-  }
-  fclose(fp);
-  return fields == 7 ? 0 : -1;
-}
-
-/*
- * Corresponds with debugger_action_t enum type in
- * include/cutils/debugger.h.
- */
-static const char *debuggerd_perms[] = {
-  NULL, /* crash is only used on self, no check applied */
-  "dump_tombstone",
-  "dump_backtrace"
-};
-
-static int audit_callback(void* data, security_class_t /* cls */, char* buf, size_t len)
-{
-    struct debugger_request_t* req = reinterpret_cast<debugger_request_t*>(data);
-
-    if (!req) {
-        ALOGE("No debuggerd request audit data");
-        return 0;
-    }
-
-    snprintf(buf, len, "pid=%d uid=%d gid=%d", req->pid, req->uid, req->gid);
-    return 0;
-}
-
-static bool selinux_action_allowed(int s, debugger_request_t* request)
-{
-  char *scon = NULL, *tcon = NULL;
-  const char *tclass = "debuggerd";
-  const char *perm;
-  bool allowed = false;
-
-  if (request->action <= 0 || request->action >= (sizeof(debuggerd_perms)/sizeof(debuggerd_perms[0]))) {
-    ALOGE("SELinux:  No permission defined for debugger action %d", request->action);
-    return false;
+  unique_fd piperead, pipewrite;
+  if (!Pipe(&piperead, &pipewrite)) {
+    err(1, "failed to create pipe");
   }
 
-  perm = debuggerd_perms[request->action];
-
-  if (getpeercon(s, &scon) < 0) {
-    ALOGE("Cannot get peer context from socket\n");
-    goto out;
+  std::thread redirect_thread = spawn_redirect_thread(std::move(piperead));
+  bool backtrace = argc == 3;
+  if (!debuggerd_trigger_dump(pid, std::move(pipewrite),
+                              backtrace ? kDebuggerdBacktrace : kDebuggerdBacktrace, 0)) {
+    redirect_thread.join();
+    errx(1, "failed to dump process %d", pid);
   }
 
-  if (getpidcon(request->tid, &tcon) < 0) {
-    ALOGE("Cannot get context for tid %d\n", request->tid);
-    goto out;
-  }
-
-  allowed = (selinux_check_access(scon, tcon, tclass, perm, reinterpret_cast<void*>(request)) == 0);
-
-out:
-   freecon(scon);
-   freecon(tcon);
-   return allowed;
-}
-
-static bool pid_contains_tid(pid_t pid, pid_t tid) {
-  char task_path[PATH_MAX];
-  if (snprintf(task_path, PATH_MAX, "/proc/%d/task/%d", pid, tid) >= PATH_MAX) {
-    ALOGE("debuggerd: task path overflow (pid = %d, tid = %d)\n", pid, tid);
-    exit(1);
-  }
-
-  return access(task_path, F_OK) == 0;
-}
-
-static int read_request(int fd, debugger_request_t* out_request) {
-  ucred cr;
-  socklen_t len = sizeof(cr);
-  int status = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cr, &len);
-  if (status != 0) {
-    ALOGE("cannot get credentials");
-    return -1;
-  }
-
-  ALOGV("reading tid");
-  pollfd pollfds[1];
-  pollfds[0].fd = fd;
-  pollfds[0].events = POLLIN;
-  pollfds[0].revents = 0;
-  status = TEMP_FAILURE_RETRY(poll(pollfds, 1, 3000));
-  if (status != 1) {
-    ALOGE("timed out reading tid (from pid=%d uid=%d)\n", cr.pid, cr.uid);
-    return -1;
-  }
-
-  debugger_msg_t msg;
-  memset(&msg, 0, sizeof(msg));
-  status = TEMP_FAILURE_RETRY(read(fd, &msg, sizeof(msg)));
-  if (status < 0) {
-    ALOGE("read failure? %s (pid=%d uid=%d)\n", strerror(errno), cr.pid, cr.uid);
-    return -1;
-  }
-  if (status != sizeof(debugger_msg_t)) {
-    ALOGE("invalid crash request of size %d (from pid=%d uid=%d)\n", status, cr.pid, cr.uid);
-    return -1;
-  }
-
-  out_request->action = static_cast<debugger_action_t>(msg.action);
-  out_request->tid = msg.tid;
-  out_request->ignore_tid = msg.ignore_tid;
-  out_request->pid = cr.pid;
-  out_request->uid = cr.uid;
-  out_request->gid = cr.gid;
-  out_request->abort_msg_address = msg.abort_msg_address;
-
-  if (msg.action == DEBUGGER_ACTION_CRASH) {
-    // Ensure that the tid reported by the crashing process is valid.
-    // This check needs to happen again after ptracing the requested thread to prevent a race.
-    if (!pid_contains_tid(out_request->pid, out_request->tid)) {
-      ALOGE("tid %d does not exist in pid %d. ignoring debug request\n", out_request->tid,
-            out_request->pid);
-      return -1;
-    }
-  } else if (cr.uid == 0 || (cr.uid == AID_SYSTEM && msg.action == DEBUGGER_ACTION_DUMP_BACKTRACE)) {
-    // Only root or system can ask us to attach to any process and dump it explicitly.
-    // However, system is only allowed to collect backtraces but cannot dump tombstones.
-    status = get_process_info(out_request->tid, &out_request->pid,
-                              &out_request->uid, &out_request->gid);
-    if (status < 0) {
-      ALOGE("tid %d does not exist. ignoring explicit dump request\n", out_request->tid);
-      return -1;
-    }
-
-    if (!selinux_action_allowed(fd, out_request))
-      return -1;
-  } else {
-    // No one else is allowed to dump arbitrary processes.
-    return -1;
-  }
+  redirect_thread.join();
   return 0;
 }
-
-static int activity_manager_connect() {
-  android::base::unique_fd amfd(socket(PF_UNIX, SOCK_STREAM, 0));
-  if (amfd.get() < -1) {
-    ALOGE("debuggerd: Unable to connect to activity manager (socket failed: %s)", strerror(errno));
-    return -1;
-  }
-
-  struct sockaddr_un address;
-  memset(&address, 0, sizeof(address));
-  address.sun_family = AF_UNIX;
-  // The path used here must match the value defined in NativeCrashListener.java.
-  strncpy(address.sun_path, "/data/system/ndebugsocket", sizeof(address.sun_path));
-  if (TEMP_FAILURE_RETRY(connect(amfd.get(), reinterpret_cast<struct sockaddr*>(&address),
-                                 sizeof(address))) == -1) {
-    ALOGE("debuggerd: Unable to connect to activity manager (connect failed: %s)", strerror(errno));
-    return -1;
-  }
-
-  struct timeval tv;
-  memset(&tv, 0, sizeof(tv));
-  tv.tv_sec = 1;  // tight leash
-  if (setsockopt(amfd.get(), SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv)) == -1) {
-    ALOGE("debuggerd: Unable to connect to activity manager (setsockopt SO_SNDTIMEO failed: %s)",
-          strerror(errno));
-    return -1;
-  }
-
-  tv.tv_sec = 3;  // 3 seconds on handshake read
-  if (setsockopt(amfd.get(), SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)) == -1) {
-    ALOGE("debuggerd: Unable to connect to activity manager (setsockopt SO_RCVTIMEO failed: %s)",
-          strerror(errno));
-    return -1;
-  }
-
-  return amfd.release();
-}
-
-static void activity_manager_write(int pid, int signal, int amfd, const std::string& amfd_data) {
-  if (amfd == -1) {
-    return;
-  }
-
-  // Activity Manager protocol: binary 32-bit network-byte-order ints for the
-  // pid and signal number, followed by the raw text of the dump, culminating
-  // in a zero byte that marks end-of-data.
-  uint32_t datum = htonl(pid);
-  if (!android::base::WriteFully(amfd, &datum, 4)) {
-    ALOGE("AM pid write failed: %s\n", strerror(errno));
-    return;
-  }
-  datum = htonl(signal);
-  if (!android::base::WriteFully(amfd, &datum, 4)) {
-    ALOGE("AM signal write failed: %s\n", strerror(errno));
-    return;
-  }
-
-  if (!android::base::WriteFully(amfd, amfd_data.c_str(), amfd_data.size())) {
-    ALOGE("AM data write failed: %s\n", strerror(errno));
-    return;
-  }
-
-  // Send EOD to the Activity Manager, then wait for its ack to avoid racing
-  // ahead and killing the target out from under it.
-  uint8_t eodMarker = 0;
-  if (!android::base::WriteFully(amfd, &eodMarker, 1)) {
-    ALOGE("AM eod write failed: %s\n", strerror(errno));
-    return;
-  }
-  // 3 sec timeout reading the ack; we're fine if the read fails.
-  android::base::ReadFully(amfd, &eodMarker, 1);
-}
-
-static bool should_attach_gdb(const debugger_request_t& request) {
-  if (request.action == DEBUGGER_ACTION_CRASH) {
-    return property_get_bool("debug.debuggerd.wait_for_gdb", false);
-  }
-  return false;
-}
-
-#if defined(__LP64__)
-static bool is32bit(pid_t tid) {
-  char* exeline;
-  if (asprintf(&exeline, "/proc/%d/exe", tid) == -1) {
-    return false;
-  }
-  int fd = TEMP_FAILURE_RETRY(open(exeline, O_RDONLY | O_CLOEXEC));
-  int saved_errno = errno;
-  free(exeline);
-  if (fd == -1) {
-    ALOGW("Failed to open /proc/%d/exe %s", tid, strerror(saved_errno));
-    return false;
-  }
-
-  char ehdr[EI_NIDENT];
-  ssize_t bytes = TEMP_FAILURE_RETRY(read(fd, &ehdr, sizeof(ehdr)));
-  close(fd);
-  if (bytes != (ssize_t) sizeof(ehdr) || memcmp(ELFMAG, ehdr, SELFMAG) != 0) {
-    return false;
-  }
-  if (ehdr[EI_CLASS] == ELFCLASS32) {
-    return true;
-  }
-  return false;
-}
-
-static void redirect_to_32(int fd, debugger_request_t* request) {
-  debugger_msg_t msg;
-  memset(&msg, 0, sizeof(msg));
-  msg.tid = request->tid;
-  msg.action = request->action;
-
-  int sock_fd = socket_local_client(DEBUGGER32_SOCKET_NAME, ANDROID_SOCKET_NAMESPACE_ABSTRACT,
-                                    SOCK_STREAM | SOCK_CLOEXEC);
-  if (sock_fd < 0) {
-    ALOGE("Failed to connect to debuggerd32: %s", strerror(errno));
-    return;
-  }
-
-  if (TEMP_FAILURE_RETRY(write(sock_fd, &msg, sizeof(msg))) != (ssize_t) sizeof(msg)) {
-    ALOGE("Failed to write request to debuggerd32 socket: %s", strerror(errno));
-    close(sock_fd);
-    return;
-  }
-
-  char ack;
-  if (TEMP_FAILURE_RETRY(read(sock_fd, &ack, 1)) == -1) {
-    ALOGE("Failed to read ack from debuggerd32 socket: %s", strerror(errno));
-    close(sock_fd);
-    return;
-  }
-
-  char buffer[1024];
-  ssize_t bytes_read;
-  while ((bytes_read = TEMP_FAILURE_RETRY(read(sock_fd, buffer, sizeof(buffer)))) > 0) {
-    ssize_t bytes_to_send = bytes_read;
-    ssize_t bytes_written;
-    do {
-      bytes_written = TEMP_FAILURE_RETRY(write(fd, buffer + bytes_read - bytes_to_send,
-                                               bytes_to_send));
-      if (bytes_written == -1) {
-        if (errno == EAGAIN) {
-          // Retry the write.
-          continue;
-        }
-        ALOGE("Error while writing data to fd: %s", strerror(errno));
-        break;
-      }
-      bytes_to_send -= bytes_written;
-    } while (bytes_written != 0 && bytes_to_send > 0);
-    if (bytes_to_send != 0) {
-        ALOGE("Failed to write all data to fd: read %zd, sent %zd", bytes_read, bytes_to_send);
-        break;
-    }
-  }
-  close(sock_fd);
-}
-#endif
-
-// Attach to a thread, and verify that it's still a member of the given process
-static bool ptrace_attach_thread(pid_t pid, pid_t tid) {
-  if (ptrace(PTRACE_ATTACH, tid, 0, 0) != 0) {
-    return false;
-  }
-
-  // Make sure that the task we attached to is actually part of the pid we're dumping.
-  if (!pid_contains_tid(pid, tid)) {
-    if (ptrace(PTRACE_DETACH, tid, 0, 0) != 0) {
-      ALOGE("debuggerd: failed to detach from thread '%d'", tid);
-      exit(1);
-    }
-    return false;
-  }
-
-  return true;
-}
-
-static void ptrace_siblings(pid_t pid, pid_t main_tid, pid_t ignore_tid, std::set<pid_t>& tids) {
-  char task_path[PATH_MAX];
-
-  if (snprintf(task_path, PATH_MAX, "/proc/%d/task", pid) >= PATH_MAX) {
-    ALOGE("debuggerd: task path overflow (pid = %d)\n", pid);
-    abort();
-  }
-
-  std::unique_ptr<DIR, int (*)(DIR*)> d(opendir(task_path), closedir);
-
-  // Bail early if the task directory cannot be opened.
-  if (!d) {
-    ALOGE("debuggerd: failed to open /proc/%d/task: %s", pid, strerror(errno));
-    return;
-  }
-
-  struct dirent* de;
-  while ((de = readdir(d.get())) != NULL) {
-    // Ignore "." and "..".
-    if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, "..")) {
-      continue;
-    }
-
-    char* end;
-    pid_t tid = strtoul(de->d_name, &end, 10);
-    if (*end) {
-      continue;
-    }
-
-    if (tid == main_tid || tid == ignore_tid) {
-      continue;
-    }
-
-    if (!ptrace_attach_thread(pid, tid)) {
-      ALOGE("debuggerd: ptrace attach to %d failed: %s", tid, strerror(errno));
-      continue;
-    }
-
-    tids.insert(tid);
-  }
-}
-
-static bool perform_dump(const debugger_request_t& request, int fd, int tombstone_fd,
-                         BacktraceMap* backtrace_map, const OpenFilesList& open_files,
-                         const std::set<pid_t>& siblings,
-                         int* crash_signal, std::string* amfd_data) {
-  if (TEMP_FAILURE_RETRY(write(fd, "\0", 1)) != 1) {
-    ALOGE("debuggerd: failed to respond to client: %s\n", strerror(errno));
-    return false;
-  }
-
-  while (true) {
-    // wait_for_signal waits for forever, but the watchdog process will kill us
-    // if it takes too long.
-    int signal = wait_for_signal(request.tid);
-    switch (signal) {
-      case -1:
-        ALOGE("debuggerd: timed out waiting for signal");
-        return false;
-
-      case SIGSTOP:
-        if (request.action == DEBUGGER_ACTION_DUMP_TOMBSTONE) {
-          ALOGV("debuggerd: stopped -- dumping to tombstone");
-          engrave_tombstone(tombstone_fd, backtrace_map, open_files,
-                            request.pid, request.tid, siblings,
-                            request.abort_msg_address, amfd_data);
-        } else if (request.action == DEBUGGER_ACTION_DUMP_BACKTRACE) {
-          ALOGV("debuggerd: stopped -- dumping to fd");
-          dump_backtrace(fd, backtrace_map, request.pid, request.tid, siblings, nullptr);
-        } else {
-          ALOGV("debuggerd: stopped -- continuing");
-          if (ptrace(PTRACE_CONT, request.tid, 0, 0) != 0) {
-            ALOGE("debuggerd: ptrace continue failed: %s", strerror(errno));
-            return false;
-          }
-          continue;  // loop again
-        }
-        break;
-
-      case SIGABRT:
-      case SIGBUS:
-      case SIGFPE:
-      case SIGILL:
-      case SIGSEGV:
-#ifdef SIGSTKFLT
-      case SIGSTKFLT:
-#endif
-      case SIGSYS:
-      case SIGTRAP:
-        ALOGV("stopped -- fatal signal\n");
-        *crash_signal = signal;
-        engrave_tombstone(tombstone_fd, backtrace_map, open_files,
-                          request.pid, request.tid, siblings,
-                          request.abort_msg_address, amfd_data);
-        break;
-
-      default:
-        ALOGE("debuggerd: process stopped due to unexpected signal %d\n", signal);
-        break;
-    }
-    break;
-  }
-
-  return true;
-}
-
-static bool drop_privileges() {
-  // AID_LOG: for reading the logs data associated with the crashing process.
-  // AID_READPROC: for reading /proc/<PID>/{comm,cmdline}.
-  gid_t groups[] = { AID_DEBUGGERD, AID_LOG, AID_READPROC };
-  if (setgroups(sizeof(groups)/sizeof(groups[0]), groups) != 0) {
-    ALOGE("debuggerd: failed to setgroups: %s", strerror(errno));
-    return false;
-  }
-
-  if (setresgid(AID_DEBUGGERD, AID_DEBUGGERD, AID_DEBUGGERD) != 0) {
-    ALOGE("debuggerd: failed to setresgid: %s", strerror(errno));
-    return false;
-  }
-
-  if (setresuid(AID_DEBUGGERD, AID_DEBUGGERD, AID_DEBUGGERD) != 0) {
-    ALOGE("debuggerd: failed to setresuid: %s", strerror(errno));
-    return false;
-  }
-
-  return true;
-}
-
-static void worker_process(int fd, debugger_request_t& request) {
-  // Open the tombstone file if we need it.
-  std::string tombstone_path;
-  int tombstone_fd = -1;
-  switch (request.action) {
-    case DEBUGGER_ACTION_DUMP_TOMBSTONE:
-    case DEBUGGER_ACTION_CRASH:
-      tombstone_fd = open_tombstone(&tombstone_path);
-      if (tombstone_fd == -1) {
-        ALOGE("debuggerd: failed to open tombstone file: %s\n", strerror(errno));
-        exit(1);
-      }
-      break;
-
-    case DEBUGGER_ACTION_DUMP_BACKTRACE:
-      break;
-
-    default:
-      ALOGE("debuggerd: unexpected request action: %d", request.action);
-      exit(1);
-  }
-
-  // At this point, the thread that made the request is blocked in
-  // a read() call.  If the thread has crashed, then this gives us
-  // time to PTRACE_ATTACH to it before it has a chance to really fault.
-  //
-  // The PTRACE_ATTACH sends a SIGSTOP to the target process, but it
-  // won't necessarily have stopped by the time ptrace() returns.  (We
-  // currently assume it does.)  We write to the file descriptor to
-  // ensure that it can run as soon as we call PTRACE_CONT below.
-  // See details in client/debuggerd_client.cpp, in function
-  // debugger_signal_handler().
-
-  // Attach to the target process.
-  if (!ptrace_attach_thread(request.pid, request.tid)) {
-    ALOGE("debuggerd: ptrace attach failed: %s", strerror(errno));
-    exit(1);
-  }
-
-  // DEBUGGER_ACTION_CRASH requests can come from arbitrary processes and the tid field in the
-  // request is sent from the other side. If an attacker can cause a process to be spawned with the
-  // pid of their process, they could trick debuggerd into dumping that process by exiting after
-  // sending the request. Validate the trusted request.uid/gid to defend against this.
-  if (request.action == DEBUGGER_ACTION_CRASH) {
-    pid_t pid;
-    uid_t uid;
-    gid_t gid;
-    if (get_process_info(request.tid, &pid, &uid, &gid) != 0) {
-      ALOGE("debuggerd: failed to get process info for tid '%d'", request.tid);
-      exit(1);
-    }
-
-    if (pid != request.pid || uid != request.uid || gid != request.gid) {
-      ALOGE(
-        "debuggerd: attached task %d does not match request: "
-        "expected pid=%d,uid=%d,gid=%d, actual pid=%d,uid=%d,gid=%d",
-        request.tid, request.pid, request.uid, request.gid, pid, uid, gid);
-      exit(1);
-    }
-  }
-
-  // Don't attach to the sibling threads if we want to attach gdb.
-  // Supposedly, it makes the process less reliable.
-  bool attach_gdb = should_attach_gdb(request);
-  if (attach_gdb) {
-    // Open all of the input devices we need to listen for VOLUMEDOWN before dropping privileges.
-    if (init_getevent() != 0) {
-      ALOGE("debuggerd: failed to initialize input device, not waiting for gdb");
-      attach_gdb = false;
-    }
-
-  }
-
-  std::set<pid_t> siblings;
-  if (!attach_gdb) {
-    ptrace_siblings(request.pid, request.tid, request.ignore_tid, siblings);
-  }
-
-  // Generate the backtrace map before dropping privileges.
-  std::unique_ptr<BacktraceMap> backtrace_map(BacktraceMap::Create(request.pid));
-
-  // Collect the list of open files before dropping privileges.
-  OpenFilesList open_files;
-  populate_open_files_list(request.pid, &open_files);
-
-  int amfd = -1;
-  std::unique_ptr<std::string> amfd_data;
-  if (request.action == DEBUGGER_ACTION_CRASH) {
-    // Connect to the activity manager before dropping privileges.
-    amfd = activity_manager_connect();
-    amfd_data.reset(new std::string);
-  }
-
-  bool succeeded = false;
-
-  // Now that we've done everything that requires privileges, we can drop them.
-  if (!drop_privileges()) {
-    ALOGE("debuggerd: failed to drop privileges, exiting");
-    _exit(1);
-  }
-
-  int crash_signal = SIGKILL;
-  succeeded = perform_dump(request, fd, tombstone_fd, backtrace_map.get(), open_files,
-                           siblings, &crash_signal, amfd_data.get());
-  if (succeeded) {
-    if (request.action == DEBUGGER_ACTION_DUMP_TOMBSTONE) {
-      if (!tombstone_path.empty()) {
-        android::base::WriteFully(fd, tombstone_path.c_str(), tombstone_path.length());
-      }
-    }
-  }
-
-  if (attach_gdb) {
-    // Tell the signal process to send SIGSTOP to the target.
-    if (!send_signal(request.pid, 0, SIGSTOP)) {
-      ALOGE("debuggerd: failed to stop process for gdb attach: %s", strerror(errno));
-      attach_gdb = false;
-    }
-  }
-
-  if (!attach_gdb) {
-    // Tell the Activity Manager about the crashing process. If we are
-    // waiting for gdb to attach, do not send this or Activity Manager
-    // might kill the process before anyone can attach.
-    activity_manager_write(request.pid, crash_signal, amfd, *amfd_data.get());
-  }
-
-  if (ptrace(PTRACE_DETACH, request.tid, 0, 0) != 0) {
-    ALOGE("debuggerd: ptrace detach from %d failed: %s", request.tid, strerror(errno));
-  }
-
-  for (pid_t sibling : siblings) {
-    ptrace(PTRACE_DETACH, sibling, 0, 0);
-  }
-
-  // Send the signal back to the process if it crashed and we're not waiting for gdb.
-  if (!attach_gdb && request.action == DEBUGGER_ACTION_CRASH) {
-    if (!send_signal(request.pid, request.tid, crash_signal)) {
-      ALOGE("debuggerd: failed to kill process %d: %s", request.pid, strerror(errno));
-    }
-  }
-
-  // Wait for gdb, if requested.
-  if (attach_gdb) {
-    wait_for_user_action(request);
-
-    // Now tell the activity manager about this process.
-    activity_manager_write(request.pid, crash_signal, amfd, *amfd_data.get());
-
-    // Tell the signal process to send SIGCONT to the target.
-    if (!send_signal(request.pid, 0, SIGCONT)) {
-      ALOGE("debuggerd: failed to resume process %d: %s", request.pid, strerror(errno));
-    }
-
-    uninit_getevent();
-  }
-
-  close(amfd);
-
-  exit(!succeeded);
-}
-
-static void monitor_worker_process(int child_pid, const debugger_request_t& request) {
-  struct timespec timeout = {.tv_sec = 10, .tv_nsec = 0 };
-  if (should_attach_gdb(request)) {
-    // If wait_for_gdb is enabled, set the timeout to something large.
-    timeout.tv_sec = INT_MAX;
-  }
-
-  sigset_t signal_set;
-  sigemptyset(&signal_set);
-  sigaddset(&signal_set, SIGCHLD);
-
-  bool kill_worker = false;
-  bool kill_target = false;
-  bool kill_self = false;
-
-  int status;
-  siginfo_t siginfo;
-  int signal = TEMP_FAILURE_RETRY(sigtimedwait(&signal_set, &siginfo, &timeout));
-  if (signal == SIGCHLD) {
-    pid_t rc = waitpid(-1, &status, WNOHANG | WUNTRACED);
-    if (rc != child_pid) {
-      ALOGE("debuggerd: waitpid returned unexpected pid (%d), committing murder-suicide", rc);
-
-      if (WIFEXITED(status)) {
-        ALOGW("debuggerd: pid %d exited with status %d", rc, WEXITSTATUS(status));
-      } else if (WIFSIGNALED(status)) {
-        ALOGW("debuggerd: pid %d received signal %d", rc, WTERMSIG(status));
-      } else if (WIFSTOPPED(status)) {
-        ALOGW("debuggerd: pid %d stopped by signal %d", rc, WSTOPSIG(status));
-      } else if (WIFCONTINUED(status)) {
-        ALOGW("debuggerd: pid %d continued", rc);
-      }
-
-      kill_worker = true;
-      kill_target = true;
-      kill_self = true;
-    } else if (WIFSIGNALED(status)) {
-      ALOGE("debuggerd: worker process %d terminated due to signal %d", child_pid, WTERMSIG(status));
-      kill_worker = false;
-      kill_target = true;
-    } else if (WIFSTOPPED(status)) {
-      ALOGE("debuggerd: worker process %d stopped due to signal %d", child_pid, WSTOPSIG(status));
-      kill_worker = true;
-      kill_target = true;
-    }
-  } else {
-    ALOGE("debuggerd: worker process %d timed out", child_pid);
-    kill_worker = true;
-    kill_target = true;
-  }
-
-  if (kill_worker) {
-    // Something bad happened, kill the worker.
-    if (kill(child_pid, SIGKILL) != 0) {
-      ALOGE("debuggerd: failed to kill worker process %d: %s", child_pid, strerror(errno));
-    } else {
-      waitpid(child_pid, &status, 0);
-    }
-  }
-
-  int exit_signal = SIGCONT;
-  if (kill_target && request.action == DEBUGGER_ACTION_CRASH) {
-    ALOGE("debuggerd: killing target %d", request.pid);
-    exit_signal = SIGKILL;
-  } else {
-    ALOGW("debuggerd: resuming target %d", request.pid);
-  }
-
-  if (kill(request.pid, exit_signal) != 0) {
-    ALOGE("debuggerd: failed to send signal %d to target: %s", exit_signal, strerror(errno));
-  }
-
-  if (kill_self) {
-    stop_signal_sender();
-    _exit(1);
-  }
-}
-
-static void handle_request(int fd) {
-  ALOGV("handle_request(%d)\n", fd);
-
-  android::base::unique_fd closer(fd);
-  debugger_request_t request;
-  memset(&request, 0, sizeof(request));
-  int status = read_request(fd, &request);
-  if (status != 0) {
-    return;
-  }
-
-  ALOGW("debuggerd: handling request: pid=%d uid=%d gid=%d tid=%d\n", request.pid, request.uid,
-        request.gid, request.tid);
-
-#if defined(__LP64__)
-  // On 64 bit systems, requests to dump 32 bit and 64 bit tids come
-  // to the 64 bit debuggerd. If the process is a 32 bit executable,
-  // redirect the request to the 32 bit debuggerd.
-  if (is32bit(request.tid)) {
-    // Only dump backtrace and dump tombstone requests can be redirected.
-    if (request.action == DEBUGGER_ACTION_DUMP_BACKTRACE ||
-        request.action == DEBUGGER_ACTION_DUMP_TOMBSTONE) {
-      redirect_to_32(fd, &request);
-    } else {
-      ALOGE("debuggerd: Not allowed to redirect action %d to 32 bit debuggerd\n", request.action);
-    }
-    return;
-  }
-#endif
-
-  // Fork a child to handle the rest of the request.
-  pid_t fork_pid = fork();
-  if (fork_pid == -1) {
-    ALOGE("debuggerd: failed to fork: %s\n", strerror(errno));
-  } else if (fork_pid == 0) {
-    worker_process(fd, request);
-  } else {
-    monitor_worker_process(fork_pid, request);
-  }
-}
-
-static int do_server() {
-  // debuggerd crashes can't be reported to debuggerd.
-  // Reset all of the crash handlers.
-  signal(SIGABRT, SIG_DFL);
-  signal(SIGBUS, SIG_DFL);
-  signal(SIGFPE, SIG_DFL);
-  signal(SIGILL, SIG_DFL);
-  signal(SIGSEGV, SIG_DFL);
-#ifdef SIGSTKFLT
-  signal(SIGSTKFLT, SIG_DFL);
-#endif
-  signal(SIGTRAP, SIG_DFL);
-
-  // Ignore failed writes to closed sockets
-  signal(SIGPIPE, SIG_IGN);
-
-  // Block SIGCHLD so we can sigtimedwait for it.
-  sigset_t sigchld;
-  sigemptyset(&sigchld);
-  sigaddset(&sigchld, SIGCHLD);
-  sigprocmask(SIG_SETMASK, &sigchld, nullptr);
-
-  int s = socket_local_server(SOCKET_NAME, ANDROID_SOCKET_NAMESPACE_ABSTRACT,
-                              SOCK_STREAM | SOCK_CLOEXEC);
-  if (s == -1) return 1;
-
-  // Fork a process that stays root, and listens on a pipe to pause and resume the target.
-  if (!start_signal_sender()) {
-    ALOGE("debuggerd: failed to fork signal sender");
-    return 1;
-  }
-
-  ALOGI("debuggerd: starting\n");
-
-  for (;;) {
-    ALOGV("waiting for connection\n");
-    int fd = accept4(s, nullptr, nullptr, SOCK_CLOEXEC | SOCK_NONBLOCK);
-    if (fd == -1) {
-      ALOGE("accept failed: %s\n", strerror(errno));
-      continue;
-    }
-
-    handle_request(fd);
-  }
-  return 0;
-}
-
-static int do_explicit_dump(pid_t tid, bool dump_backtrace) {
-  fprintf(stdout, "Sending request to dump task %d...\n", tid);
-  fflush(stdout);
-
-  // TODO: we could have better error reporting if debuggerd sent an error string back.
-  if (dump_backtrace) {
-    if (dump_backtrace_to_file(tid, fileno(stdout)) < 0) {
-      fputs("Error dumping backtrace (check logcat).\n", stderr);
-      return 1;
-    }
-  } else {
-    char tombstone_path[PATH_MAX];
-    if (dump_tombstone(tid, tombstone_path, sizeof(tombstone_path)) < 0) {
-      fputs("Error dumping tombstone (check logcat).\n", stderr);
-      return 1;
-    }
-    fprintf(stderr, "Tombstone written to: %s\n", tombstone_path);
-  }
-  return 0;
-}
-
-static int usage() {
-  fputs("usage: debuggerd [-b] [<tid>]\n"
-        "\n"
-        "Given a thread id, sends a request to debuggerd to dump that thread.\n"
-        "Otherwise, starts the debuggerd server.\n"
-        "\n"
-        "-b\tdump backtrace to console, otherwise generate tombstone\n", stderr);
-  return EXIT_FAILURE;
-}
-
-int main(int argc, char** argv) {
-  union selinux_callback cb;
-  if (argc == 1) {
-    cb.func_audit = audit_callback;
-    selinux_set_callback(SELINUX_CB_AUDIT, cb);
-    cb.func_log = selinux_log_callback;
-    selinux_set_callback(SELINUX_CB_LOG, cb);
-    return do_server();
-  }
-
-  bool dump_backtrace = false;
-  pid_t tid = 0;
-  for (int i = 1; i < argc; i++) {
-    if (!strcmp(argv[i], "-b")) {
-      dump_backtrace = true;
-    } else if (tid != 0 || (tid = atoi(argv[i])) == 0) {
-      // Only one tid is allowed. (And 0 isn't a valid tid.)
-      // atoi(3) returns 0 on failure to parse, so this catches anything else too.
-      return usage();
-    }
-  }
-  return (tid != 0) ? do_explicit_dump(tid, dump_backtrace) : usage();
-}
diff --git a/debuggerd/debuggerd.rc b/debuggerd/debuggerd.rc
deleted file mode 100644
index 1c6b9ff..0000000
--- a/debuggerd/debuggerd.rc
+++ /dev/null
@@ -1,3 +0,0 @@
-service debuggerd /system/bin/debuggerd
-    group root readproc
-    writepid /dev/cpuset/system-background/tasks
diff --git a/debuggerd/debuggerd64.rc b/debuggerd/debuggerd64.rc
deleted file mode 100644
index 3e8847a..0000000
--- a/debuggerd/debuggerd64.rc
+++ /dev/null
@@ -1,3 +0,0 @@
-service debuggerd64 /system/bin/debuggerd64
-    group root readproc
-    writepid /dev/cpuset/system-background/tasks
diff --git a/debuggerd/debuggerd_test.cpp b/debuggerd/debuggerd_test.cpp
new file mode 100644
index 0000000..f51b5f2
--- /dev/null
+++ b/debuggerd/debuggerd_test.cpp
@@ -0,0 +1,390 @@
+/*
+ * 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 <err.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/types.h>
+
+#include <chrono>
+#include <regex>
+#include <thread>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/parseint.h>
+#include <android-base/properties.h>
+#include <android-base/strings.h>
+#include <android-base/unique_fd.h>
+#include <cutils/sockets.h>
+#include <debuggerd/handler.h>
+#include <debuggerd/protocol.h>
+#include <debuggerd/util.h>
+#include <gtest/gtest.h>
+
+using namespace std::chrono_literals;
+using android::base::unique_fd;
+
+#if defined(__LP64__)
+#define CRASHER_PATH  "/system/xbin/crasher64"
+#define ARCH_SUFFIX "64"
+#else
+#define CRASHER_PATH "/system/xbin/crasher"
+#define ARCH_SUFFIX ""
+#endif
+
+constexpr char kWaitForGdbKey[] = "debug.debuggerd.wait_for_gdb";
+
+#define TIMEOUT(seconds, expr)                                     \
+  [&]() {                                                          \
+    struct sigaction old_sigaction;                                \
+    struct sigaction new_sigaction = {};                           \
+    new_sigaction.sa_handler = [](int) {};                         \
+    if (sigaction(SIGALRM, &new_sigaction, &new_sigaction) != 0) { \
+      err(1, "sigaction failed");                                  \
+    }                                                              \
+    alarm(seconds);                                                \
+    auto value = expr;                                             \
+    int saved_errno = errno;                                       \
+    if (sigaction(SIGALRM, &old_sigaction, nullptr) != 0) {        \
+      err(1, "sigaction failed");                                  \
+    }                                                              \
+    alarm(0);                                                      \
+    errno = saved_errno;                                           \
+    return value;                                                  \
+  }()
+
+#define ASSERT_MATCH(str, pattern)                                              \
+  do {                                                                          \
+    std::regex r((pattern));                                                    \
+    if (!std::regex_search((str), r)) {                                         \
+      FAIL() << "regex mismatch: expected " << (pattern) << " in: \n" << (str); \
+    }                                                                           \
+  } while (0)
+
+class CrasherTest : public ::testing::Test {
+ public:
+  pid_t crasher_pid = -1;
+  bool previous_wait_for_gdb;
+  unique_fd crasher_pipe;
+  unique_fd intercept_fd;
+
+  CrasherTest();
+  ~CrasherTest();
+
+  void StartIntercept(unique_fd* output_fd);
+
+  // Returns -1 if we fail to read a response from tombstoned, otherwise the received return code.
+  void FinishIntercept(int* result);
+
+  void StartCrasher(const std::string& crash_type);
+  void FinishCrasher();
+  void AssertDeath(int signo);
+};
+
+CrasherTest::CrasherTest() {
+  previous_wait_for_gdb = android::base::GetBoolProperty(kWaitForGdbKey, false);
+  android::base::SetProperty(kWaitForGdbKey, "0");
+}
+
+CrasherTest::~CrasherTest() {
+  if (crasher_pid != -1) {
+    kill(crasher_pid, SIGKILL);
+    int status;
+    waitpid(crasher_pid, &status, WUNTRACED);
+  }
+
+  android::base::SetProperty(kWaitForGdbKey, previous_wait_for_gdb ? "1" : "0");
+}
+
+void CrasherTest::StartIntercept(unique_fd* output_fd) {
+  if (crasher_pid == -1) {
+    FAIL() << "crasher hasn't been started";
+  }
+
+  intercept_fd.reset(socket_local_client(kTombstonedInterceptSocketName,
+                                         ANDROID_SOCKET_NAMESPACE_RESERVED, SOCK_SEQPACKET));
+  if (intercept_fd == -1) {
+    FAIL() << "failed to contact tombstoned: " << strerror(errno);
+  }
+
+  InterceptRequest req = {.pid = crasher_pid };
+
+  unique_fd output_pipe_write;
+  if (!Pipe(output_fd, &output_pipe_write)) {
+    FAIL() << "failed to create output pipe: " << strerror(errno);
+  }
+
+  std::string pipe_size_str;
+  int pipe_buffer_size;
+  if (!android::base::ReadFileToString("/proc/sys/fs/pipe-max-size", &pipe_size_str)) {
+    FAIL() << "failed to read /proc/sys/fs/pipe-max-size: " << strerror(errno);
+  }
+
+  pipe_size_str = android::base::Trim(pipe_size_str);
+
+  if (!android::base::ParseInt(pipe_size_str.c_str(), &pipe_buffer_size, 0)) {
+    FAIL() << "failed to parse pipe max size";
+  }
+
+  if (fcntl(output_fd->get(), F_SETPIPE_SZ, pipe_buffer_size) != pipe_buffer_size) {
+    FAIL() << "failed to set pipe size: " << strerror(errno);
+  }
+
+  if (send_fd(intercept_fd.get(), &req, sizeof(req), std::move(output_pipe_write)) != sizeof(req)) {
+    FAIL() << "failed to send output fd to tombstoned: " << strerror(errno);
+  }
+}
+
+void CrasherTest::FinishIntercept(int* result) {
+  InterceptResponse response;
+
+  // Timeout for tombstoned intercept is 10 seconds.
+  ssize_t rc = TIMEOUT(20, read(intercept_fd.get(), &response, sizeof(response)));
+  if (rc == -1) {
+    FAIL() << "failed to read response from tombstoned: " << strerror(errno);
+  } else if (rc == 0) {
+    *result = -1;
+  } else if (rc != sizeof(response)) {
+    FAIL() << "received packet of unexpected length from tombstoned: expected " << sizeof(response)
+           << ", received " << rc;
+  } else {
+    *result = response.success;
+  }
+}
+
+void CrasherTest::StartCrasher(const std::string& crash_type) {
+  std::string type = "wait-" + crash_type;
+
+  unique_fd crasher_read_pipe;
+  if (!Pipe(&crasher_read_pipe, &crasher_pipe)) {
+    FAIL() << "failed to create pipe: " << strerror(errno);
+  }
+
+  crasher_pid = fork();
+  if (crasher_pid == -1) {
+    FAIL() << "fork failed: " << strerror(errno);
+  } else if (crasher_pid == 0) {
+    unique_fd devnull(open("/dev/null", O_WRONLY));
+    dup2(crasher_read_pipe.get(), STDIN_FILENO);
+    dup2(devnull.get(), STDOUT_FILENO);
+    dup2(devnull.get(), STDERR_FILENO);
+    execl(CRASHER_PATH, CRASHER_PATH, type.c_str(), nullptr);
+    err(1, "exec failed");
+  }
+}
+
+void CrasherTest::FinishCrasher() {
+  if (crasher_pipe == -1) {
+    FAIL() << "crasher pipe uninitialized";
+  }
+
+  ssize_t rc = write(crasher_pipe.get(), "\n", 1);
+  if (rc == -1) {
+    FAIL() << "failed to write to crasher pipe: " << strerror(errno);
+  } else if (rc == 0) {
+    FAIL() << "crasher pipe was closed";
+  }
+}
+
+void CrasherTest::AssertDeath(int signo) {
+  int status;
+  pid_t pid = TIMEOUT(5, waitpid(crasher_pid, &status, 0));
+  if (pid != crasher_pid) {
+    FAIL() << "failed to wait for crasher: " << strerror(errno);
+  }
+
+  if (!WIFSIGNALED(status)) {
+    FAIL() << "crasher didn't terminate via a signal";
+  }
+  ASSERT_EQ(signo, WTERMSIG(status));
+  crasher_pid = -1;
+}
+
+static void ConsumeFd(unique_fd fd, std::string* output) {
+  constexpr size_t read_length = PAGE_SIZE;
+  std::string result;
+
+  while (true) {
+    size_t offset = result.size();
+    result.resize(result.size() + PAGE_SIZE);
+    ssize_t rc = TEMP_FAILURE_RETRY(read(fd.get(), &result[offset], read_length));
+    if (rc == -1) {
+      FAIL() << "read failed: " << strerror(errno);
+    } else if (rc == 0) {
+      result.resize(result.size() - PAGE_SIZE);
+      break;
+    }
+
+    result.resize(result.size() - PAGE_SIZE + rc);
+  }
+
+  *output = std::move(result);
+}
+
+TEST_F(CrasherTest, smoke) {
+  int intercept_result;
+  unique_fd output_fd;
+  StartCrasher("SIGSEGV");
+  StartIntercept(&output_fd);
+  FinishCrasher();
+  AssertDeath(SIGSEGV);
+  FinishIntercept(&intercept_result);
+
+  ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
+
+  std::string result;
+  ConsumeFd(std::move(output_fd), &result);
+  ASSERT_MATCH(result, R"(signal 11 \(SIGSEGV\), code 1 \(SEGV_MAPERR\), fault addr 0xdead)");
+}
+
+TEST_F(CrasherTest, abort) {
+  int intercept_result;
+  unique_fd output_fd;
+  StartCrasher("abort");
+  StartIntercept(&output_fd);
+  FinishCrasher();
+  AssertDeath(SIGABRT);
+  FinishIntercept(&intercept_result);
+
+  ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
+
+  std::string result;
+  ConsumeFd(std::move(output_fd), &result);
+  ASSERT_MATCH(result, R"(#00 pc [0-9a-f]+\s+ /system/lib)" ARCH_SUFFIX R"(/libc.so \(tgkill)");
+}
+
+TEST_F(CrasherTest, signal) {
+  int intercept_result;
+  unique_fd output_fd;
+  StartCrasher("abort");
+  StartIntercept(&output_fd);
+
+  // Wait for a bit, or we might end up killing the process before the signal
+  // handler even gets a chance to be registered.
+  std::this_thread::sleep_for(100ms);
+  ASSERT_EQ(0, kill(crasher_pid, SIGSEGV));
+
+  AssertDeath(SIGSEGV);
+  FinishIntercept(&intercept_result);
+
+  ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
+
+  std::string result;
+  ConsumeFd(std::move(output_fd), &result);
+  ASSERT_MATCH(result, R"(signal 11 \(SIGSEGV\), code 0 \(SI_USER\), fault addr --------)");
+  ASSERT_MATCH(result, R"(backtrace:)");
+}
+
+TEST_F(CrasherTest, abort_message) {
+  int intercept_result;
+  unique_fd output_fd;
+  StartCrasher("smash-stack");
+  StartIntercept(&output_fd);
+  FinishCrasher();
+  AssertDeath(SIGABRT);
+  FinishIntercept(&intercept_result);
+
+  ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
+
+  std::string result;
+  ConsumeFd(std::move(output_fd), &result);
+  ASSERT_MATCH(result, R"(Abort message: 'stack corruption detected \(-fstack-protector\)')");
+}
+
+TEST_F(CrasherTest, intercept_timeout) {
+  int intercept_result;
+  unique_fd output_fd;
+  StartCrasher("abort");
+  StartIntercept(&output_fd);
+
+  // Don't let crasher finish until we timeout.
+  FinishIntercept(&intercept_result);
+
+  ASSERT_NE(1, intercept_result) << "tombstoned reported success? (intercept_result = "
+                                 << intercept_result << ")";
+
+  FinishCrasher();
+  AssertDeath(SIGABRT);
+}
+
+TEST_F(CrasherTest, wait_for_gdb) {
+  if (!android::base::SetProperty(kWaitForGdbKey, "1")) {
+    FAIL() << "failed to enable wait_for_gdb";
+  }
+  sleep(1);
+
+  StartCrasher("abort");
+  FinishCrasher();
+
+  int status;
+  ASSERT_EQ(crasher_pid, waitpid(crasher_pid, &status, WUNTRACED));
+  ASSERT_TRUE(WIFSTOPPED(status));
+  ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
+
+  ASSERT_EQ(0, kill(crasher_pid, SIGCONT));
+
+  AssertDeath(SIGABRT);
+}
+
+TEST_F(CrasherTest, wait_for_gdb_signal) {
+  if (!android::base::SetProperty(kWaitForGdbKey, "1")) {
+    FAIL() << "failed to enable wait_for_gdb";
+  }
+
+  StartCrasher("abort");
+  ASSERT_EQ(0, kill(crasher_pid, SIGABRT)) << strerror(errno);
+
+  std::this_thread::sleep_for(500ms);
+
+  int status;
+  ASSERT_EQ(crasher_pid, (TIMEOUT(1, waitpid(crasher_pid, &status, WUNTRACED))));
+  ASSERT_TRUE(WIFSTOPPED(status));
+  ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
+
+  ASSERT_EQ(0, kill(crasher_pid, SIGCONT)) << strerror(errno);
+
+  AssertDeath(SIGABRT);
+}
+
+TEST_F(CrasherTest, backtrace) {
+  std::string result;
+  int intercept_result;
+  unique_fd output_fd;
+  StartCrasher("abort");
+  StartIntercept(&output_fd);
+
+  std::this_thread::sleep_for(500ms);
+
+  sigval val;
+  val.sival_int = 1;
+  ASSERT_EQ(0, sigqueue(crasher_pid, DEBUGGER_SIGNAL, val)) << strerror(errno);
+  FinishIntercept(&intercept_result);
+  ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
+  ConsumeFd(std::move(output_fd), &result);
+  ASSERT_MATCH(result, R"(#00 pc [0-9a-f]+  /system/lib)" ARCH_SUFFIX R"(/libc.so \(read\+)");
+
+  int status;
+  ASSERT_EQ(0, waitpid(crasher_pid, &status, WNOHANG | WUNTRACED));
+
+  StartIntercept(&output_fd);
+  FinishCrasher();
+  AssertDeath(SIGABRT);
+  FinishIntercept(&intercept_result);
+  ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
+  ConsumeFd(std::move(output_fd), &result);
+  ASSERT_MATCH(result, R"(#00 pc [0-9a-f]+\s+ /system/lib)" ARCH_SUFFIX R"(/libc.so \(tgkill)");
+}
diff --git a/debuggerd/getevent.cpp b/debuggerd/getevent.cpp
deleted file mode 100644
index dbb878a..0000000
--- a/debuggerd/getevent.cpp
+++ /dev/null
@@ -1,224 +0,0 @@
-/*
- * Copyright (C) 2014 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include <dirent.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <linux/input.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/inotify.h>
-#include <sys/ioctl.h>
-#include <sys/limits.h>
-#include <sys/poll.h>
-#include <unistd.h>
-
-#include <memory>
-
-#include <android/log.h>
-
-static struct pollfd* ufds;
-static char** device_names;
-static int nfds;
-
-static int open_device(const char* device) {
-  int version;
-  int fd;
-  struct pollfd* new_ufds;
-  char** new_device_names;
-  char name[80];
-  char location[80];
-  char idstr[80];
-  struct input_id id;
-
-  fd = open(device, O_RDWR);
-  if (fd < 0) {
-    return -1;
-  }
-
-  if (ioctl(fd, EVIOCGVERSION, &version)) {
-    return -1;
-  }
-  if (ioctl(fd, EVIOCGID, &id)) {
-    return -1;
-  }
-  name[sizeof(name) - 1] = '\0';
-  location[sizeof(location) - 1] = '\0';
-  idstr[sizeof(idstr) - 1] = '\0';
-  if (ioctl(fd, EVIOCGNAME(sizeof(name) - 1), &name) < 1) {
-    name[0] = '\0';
-  }
-  if (ioctl(fd, EVIOCGPHYS(sizeof(location) - 1), &location) < 1) {
-    location[0] = '\0';
-  }
-  if (ioctl(fd, EVIOCGUNIQ(sizeof(idstr) - 1), &idstr) < 1) {
-    idstr[0] = '\0';
-  }
-
-  new_ufds = reinterpret_cast<pollfd*>(realloc(ufds, sizeof(ufds[0]) * (nfds + 1)));
-  if (new_ufds == NULL) {
-    fprintf(stderr, "out of memory\n");
-    return -1;
-  }
-  ufds = new_ufds;
-  new_device_names = reinterpret_cast<char**>(realloc(
-      device_names, sizeof(device_names[0]) * (nfds + 1)));
-  if (new_device_names == NULL) {
-    fprintf(stderr, "out of memory\n");
-    return -1;
-  }
-  device_names = new_device_names;
-  ufds[nfds].fd = fd;
-  ufds[nfds].events = POLLIN;
-  device_names[nfds] = strdup(device);
-  nfds++;
-
-  return 0;
-}
-
-int close_device(const char* device) {
-  int i;
-  for (i = 1; i < nfds; i++) {
-    if (strcmp(device_names[i], device) == 0) {
-      int count = nfds - i - 1;
-      free(device_names[i]);
-      memmove(device_names + i, device_names + i + 1, sizeof(device_names[0]) * count);
-      memmove(ufds + i, ufds + i + 1, sizeof(ufds[0]) * count);
-      nfds--;
-      return 0;
-    }
-  }
-  return -1;
-}
-
-static int read_notify(const char* dirname, int nfd) {
-  int res;
-  char devname[PATH_MAX];
-  char* filename;
-  char event_buf[512];
-  int event_size;
-  int event_pos = 0;
-  struct inotify_event *event;
-
-  res = read(nfd, event_buf, sizeof(event_buf));
-  if (res < (int)sizeof(*event)) {
-    if (errno == EINTR)
-      return 0;
-    fprintf(stderr, "could not get event, %s\n", strerror(errno));
-    return 1;
-  }
-
-  strcpy(devname, dirname);
-  filename = devname + strlen(devname);
-  *filename++ = '/';
-
-  while (res >= (int)sizeof(*event)) {
-    event = reinterpret_cast<struct inotify_event*>(event_buf + event_pos);
-    if (event->len) {
-      strcpy(filename, event->name);
-      if (event->mask & IN_CREATE) {
-        open_device(devname);
-      } else {
-        close_device(devname);
-      }
-    }
-    event_size = sizeof(*event) + event->len;
-    res -= event_size;
-    event_pos += event_size;
-  }
-  return 0;
-}
-
-static int scan_dir(const char* dirname) {
-  char devname[PATH_MAX];
-  char* filename;
-  struct dirent* de;
-  std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(dirname), closedir);
-  if (dir == NULL)
-    return -1;
-  strcpy(devname, dirname);
-  filename = devname + strlen(devname);
-  *filename++ = '/';
-  while ((de = readdir(dir.get()))) {
-    if ((de->d_name[0] == '.' && de->d_name[1] == '\0') ||
-        (de->d_name[1] == '.' && de->d_name[2] == '\0'))
-      continue;
-    strcpy(filename, de->d_name);
-    open_device(devname);
-  }
-  return 0;
-}
-
-int init_getevent() {
-  int res;
-  const char* device_path = "/dev/input";
-
-  nfds = 1;
-  ufds = reinterpret_cast<pollfd*>(calloc(1, sizeof(ufds[0])));
-  ufds[0].fd = inotify_init();
-  ufds[0].events = POLLIN;
-
-  res = inotify_add_watch(ufds[0].fd, device_path, IN_DELETE | IN_CREATE);
-  if (res < 0) {
-    return 1;
-  }
-  res = scan_dir(device_path);
-  if (res < 0) {
-    return 1;
-  }
-  return 0;
-}
-
-void uninit_getevent() {
-  int i;
-  for (i = 0; i < nfds; i++) {
-    close(ufds[i].fd);
-  }
-  free(ufds);
-  ufds = 0;
-  nfds = 0;
-}
-
-int get_event(struct input_event* event, int timeout) {
-  int res;
-  int i;
-  int pollres;
-  const char* device_path = "/dev/input";
-  while (1) {
-    pollres = poll(ufds, nfds, timeout);
-    if (pollres == 0) {
-      return 1;
-    }
-    if (ufds[0].revents & POLLIN) {
-      read_notify(device_path, ufds[0].fd);
-    }
-    for (i = 1; i < nfds; i++) {
-      if (ufds[i].revents) {
-        if (ufds[i].revents & POLLIN) {
-          res = read(ufds[i].fd, event, sizeof(*event));
-          if (res < static_cast<int>(sizeof(event))) {
-            fprintf(stderr, "could not get event\n");
-            return -1;
-          }
-          return 0;
-        }
-      }
-    }
-  }
-  return 0;
-}
diff --git a/debuggerd/getevent.h b/debuggerd/getevent.h
deleted file mode 100644
index 426139d..0000000
--- a/debuggerd/getevent.h
+++ /dev/null
@@ -1,24 +0,0 @@
-/*
- * Copyright (C) 2011 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.
- */
-
-#ifndef _DEBUGGERD_GETEVENT_H
-#define _DEBUGGERD_GETEVENT_H
-
-int init_getevent();
-void uninit_getevent();
-int get_event(struct input_event* event, int timeout);
-
-#endif // _DEBUGGERD_GETEVENT_H
diff --git a/debuggerd/handler/debuggerd_handler.cpp b/debuggerd/handler/debuggerd_handler.cpp
new file mode 100644
index 0000000..6033a6b
--- /dev/null
+++ b/debuggerd/handler/debuggerd_handler.cpp
@@ -0,0 +1,377 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "debuggerd/handler.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <pthread.h>
+#include <sched.h>
+#include <signal.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/prctl.h>
+#include <sys/socket.h>
+#include <sys/syscall.h>
+#include <sys/un.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "private/libc_logging.h"
+
+// see man(2) prctl, specifically the section about PR_GET_NAME
+#define MAX_TASK_NAME_LEN (16)
+
+#if defined(__LP64__)
+#define CRASH_DUMP_NAME "crash_dump64"
+#else
+#define CRASH_DUMP_NAME "crash_dump32"
+#endif
+
+#define CRASH_DUMP_PATH "/system/bin/" CRASH_DUMP_NAME
+
+static debuggerd_callbacks_t g_callbacks;
+
+// Don't use __libc_fatal because it exits via abort, which might put us back into a signal handler.
+#define fatal(...)                                             \
+  do {                                                         \
+    __libc_format_log(ANDROID_LOG_FATAL, "libc", __VA_ARGS__); \
+    _exit(1);                                                  \
+  } while (0)
+
+/*
+ * Writes a summary of the signal to the log file.  We do this so that, if
+ * for some reason we're not able to contact debuggerd, there is still some
+ * indication of the failure in the log.
+ *
+ * We could be here as a result of native heap corruption, or while a
+ * mutex is being held, so we don't want to use any libc functions that
+ * could allocate memory or hold a lock.
+ */
+static void log_signal_summary(int signum, const siginfo_t* info) {
+  const char* signal_name = "???";
+  bool has_address = false;
+  switch (signum) {
+    case SIGABRT:
+      signal_name = "SIGABRT";
+      break;
+    case SIGBUS:
+      signal_name = "SIGBUS";
+      has_address = true;
+      break;
+    case SIGFPE:
+      signal_name = "SIGFPE";
+      has_address = true;
+      break;
+    case SIGILL:
+      signal_name = "SIGILL";
+      has_address = true;
+      break;
+    case SIGSEGV:
+      signal_name = "SIGSEGV";
+      has_address = true;
+      break;
+#if defined(SIGSTKFLT)
+    case SIGSTKFLT:
+      signal_name = "SIGSTKFLT";
+      break;
+#endif
+    case SIGSYS:
+      signal_name = "SIGSYS";
+      break;
+    case SIGTRAP:
+      signal_name = "SIGTRAP";
+      break;
+  }
+
+  char thread_name[MAX_TASK_NAME_LEN + 1];  // one more for termination
+  if (prctl(PR_GET_NAME, reinterpret_cast<unsigned long>(thread_name), 0, 0, 0) != 0) {
+    strcpy(thread_name, "<name unknown>");
+  } else {
+    // short names are null terminated by prctl, but the man page
+    // implies that 16 byte names are not.
+    thread_name[MAX_TASK_NAME_LEN] = 0;
+  }
+
+  // "info" will be null if the siginfo_t information was not available.
+  // Many signals don't have an address or a code.
+  char code_desc[32];  // ", code -6"
+  char addr_desc[32];  // ", fault addr 0x1234"
+  addr_desc[0] = code_desc[0] = 0;
+  if (info != nullptr) {
+    __libc_format_buffer(code_desc, sizeof(code_desc), ", code %d", info->si_code);
+    if (has_address) {
+      __libc_format_buffer(addr_desc, sizeof(addr_desc), ", fault addr %p", info->si_addr);
+    }
+  }
+  __libc_format_log(ANDROID_LOG_FATAL, "libc", "Fatal signal %d (%s)%s%s in tid %d (%s)", signum,
+                    signal_name, code_desc, addr_desc, gettid(), thread_name);
+}
+
+/*
+ * Returns true if the handler for signal "signum" has SA_SIGINFO set.
+ */
+static bool have_siginfo(int signum) {
+  struct sigaction old_action;
+  if (sigaction(signum, nullptr, &old_action) < 0) {
+    __libc_format_log(ANDROID_LOG_WARN, "libc", "Failed testing for SA_SIGINFO: %s",
+                      strerror(errno));
+    return false;
+  }
+  return (old_action.sa_flags & SA_SIGINFO) != 0;
+}
+
+struct debugger_thread_info {
+  pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+  bool crash_dump_started = false;
+  pid_t crashing_tid;
+  pid_t pseudothread_tid;
+  int signal_number;
+  siginfo_t* info;
+};
+
+// Logging and contacting debuggerd requires free file descriptors, which we might not have.
+// Work around this by spawning a "thread" that shares its parent's address space, but not its file
+// descriptor table, so that we can close random file descriptors without affecting the original
+// process. Note that this doesn't go through pthread_create, so TLS is shared with the spawning
+// process.
+static void* pseudothread_stack;
+
+static int debuggerd_dispatch_pseudothread(void* arg) {
+  debugger_thread_info* thread_info = static_cast<debugger_thread_info*>(arg);
+
+  for (int i = 0; i < 1024; ++i) {
+    close(i);
+  }
+
+  int devnull = TEMP_FAILURE_RETRY(open("/dev/null", O_RDWR));
+
+  // devnull will be 0.
+  TEMP_FAILURE_RETRY(dup2(devnull, STDOUT_FILENO));
+  TEMP_FAILURE_RETRY(dup2(devnull, STDERR_FILENO));
+
+  int pipefds[2];
+  if (pipe(pipefds) != 0) {
+    fatal("failed to create pipe");
+  }
+
+  // Don't use fork(2) to avoid calling pthread_atfork handlers.
+  int forkpid = clone(nullptr, nullptr, SIGCHLD, nullptr);
+  if (forkpid == -1) {
+    __libc_format_log(ANDROID_LOG_FATAL, "libc", "failed to fork in debuggerd signal handler: %s",
+                      strerror(errno));
+  } else if (forkpid == 0) {
+    TEMP_FAILURE_RETRY(dup2(pipefds[1], STDOUT_FILENO));
+    close(pipefds[0]);
+    close(pipefds[1]);
+
+    char buf[10];
+    snprintf(buf, sizeof(buf), "%d", thread_info->crashing_tid);
+    execl(CRASH_DUMP_PATH, CRASH_DUMP_NAME, buf, nullptr);
+
+    fatal("exec failed: %s", strerror(errno));
+  } else {
+    close(pipefds[1]);
+    char buf[4];
+    ssize_t rc = TEMP_FAILURE_RETRY(read(pipefds[0], &buf, sizeof(buf)));
+    if (rc == -1) {
+      __libc_format_log(ANDROID_LOG_FATAL, "libc", "read of IPC pipe failed: %s", strerror(errno));
+    } else if (rc == 0) {
+      __libc_format_log(ANDROID_LOG_FATAL, "libc", "crash_dump helper failed to exec");
+    } else if (rc != 1) {
+      __libc_format_log(ANDROID_LOG_FATAL, "libc",
+                        "read of IPC pipe returned unexpected value: %zd", rc);
+    } else {
+      if (buf[0] != '\1') {
+        __libc_format_log(ANDROID_LOG_FATAL, "libc", "crash_dump helper reported failure");
+      } else {
+        thread_info->crash_dump_started = true;
+      }
+    }
+    close(pipefds[0]);
+
+    // Don't leave a zombie child.
+    siginfo_t child_siginfo;
+    if (TEMP_FAILURE_RETRY(waitid(P_PID, forkpid, &child_siginfo, WEXITED)) != 0) {
+      __libc_format_log(ANDROID_LOG_FATAL, "libc", "failed to wait for crash_dump helper: %s",
+                        strerror(errno));
+      thread_info->crash_dump_started = false;
+    }
+  }
+
+  pthread_mutex_unlock(&thread_info->mutex);
+  return 0;
+}
+
+// Handler that does crash dumping by forking and doing the processing in the child.
+// Do this by ptracing the relevant thread, and then execing debuggerd to do the actual dump.
+static void debuggerd_signal_handler(int signal_number, siginfo_t* info, void*) {
+  // Mutex to prevent multiple crashing threads from trying to talk
+  // to debuggerd at the same time.
+  static pthread_mutex_t crash_mutex = PTHREAD_MUTEX_INITIALIZER;
+  int ret = pthread_mutex_lock(&crash_mutex);
+  if (ret != 0) {
+    __libc_format_log(ANDROID_LOG_INFO, "libc", "pthread_mutex_lock failed: %s", strerror(ret));
+    return;
+  }
+
+  // It's possible somebody cleared the SA_SIGINFO flag, which would mean
+  // our "info" arg holds an undefined value.
+  if (!have_siginfo(signal_number)) {
+    info = nullptr;
+  }
+
+  log_signal_summary(signal_number, info);
+  if (prctl(PR_GET_DUMPABLE, 0, 0, 0, 0) == 0) {
+    // process has disabled core dumps and PTRACE_ATTACH, and does not want to be dumped.
+    // Honor that intention by not connecting to debuggerd and asking it to dump our internal state.
+    __libc_format_log(ANDROID_LOG_INFO, "libc",
+                      "Suppressing debuggerd output because prctl(PR_GET_DUMPABLE)==0");
+
+    pthread_mutex_unlock(&crash_mutex);
+    return;
+  }
+
+  void* abort_message = nullptr;
+  if (g_callbacks.get_abort_message) {
+    abort_message = g_callbacks.get_abort_message();
+  }
+
+  debugger_thread_info thread_info = {
+    .crashing_tid = gettid(),
+    .signal_number = signal_number,
+    .info = info
+  };
+  pthread_mutex_lock(&thread_info.mutex);
+
+  // Essentially pthread_create without CLONE_FILES (see debuggerd_dispatch_pseudothread).
+  pid_t child_pid = clone(debuggerd_dispatch_pseudothread, pseudothread_stack,
+                          CLONE_THREAD | CLONE_SIGHAND | CLONE_VM | CLONE_CHILD_SETTID,
+                          &thread_info, nullptr, nullptr, &thread_info.pseudothread_tid);
+  if (child_pid == -1) {
+    fatal("failed to spawn debuggerd dispatch thread: %s", strerror(errno));
+  }
+
+  // Wait for the child to finish and unlock the mutex.
+  // This relies on bionic behavior that isn't guaranteed by the standard.
+  pthread_mutex_lock(&thread_info.mutex);
+
+  // Signals can either be fatal or nonfatal.
+  // For fatal signals, crash_dump will PTRACE_CONT us with the signal we
+  // crashed with, so that processes using waitpid on us will see that we
+  // exited with the correct exit status (e.g. so that sh will report
+  // "Segmentation fault" instead of "Killed"). For this to work, we need
+  // to deregister our signal handler for that signal before continuing.
+  if (signal_number != DEBUGGER_SIGNAL) {
+    signal(signal_number, SIG_DFL);
+  }
+
+  // We need to return from the signal handler so that debuggerd can dump the
+  // thread that crashed, but returning here does not guarantee that the signal
+  // will be thrown again, even for SIGSEGV and friends, since the signal could
+  // have been sent manually. Resend the signal with rt_tgsigqueueinfo(2) to
+  // preserve the SA_SIGINFO contents.
+  struct siginfo si;
+  if (!info) {
+    memset(&si, 0, sizeof(si));
+    si.si_code = SI_USER;
+    si.si_pid = getpid();
+    si.si_uid = getuid();
+    info = &si;
+  } else if (info->si_code >= 0 || info->si_code == SI_TKILL) {
+    // rt_tgsigqueueinfo(2)'s documentation appears to be incorrect on kernels
+    // that contain commit 66dd34a (3.9+). The manpage claims to only allow
+    // negative si_code values that are not SI_TKILL, but 66dd34a changed the
+    // check to allow all si_code values in calls coming from inside the house.
+  }
+
+  // Populate si_value with the abort message address, if found.
+  if (abort_message) {
+    info->si_value.sival_ptr = abort_message;
+  }
+
+  // Only resend the signal if we know that either crash_dump has ptraced us or
+  // the signal was fatal.
+  if (thread_info.crash_dump_started || signal_number != DEBUGGER_SIGNAL) {
+    int rc = syscall(SYS_rt_tgsigqueueinfo, getpid(), gettid(), signal_number, info);
+    if (rc != 0) {
+      fatal("failed to resend signal during crash: %s", strerror(errno));
+    }
+  }
+
+  if (signal_number == DEBUGGER_SIGNAL) {
+    pthread_mutex_unlock(&crash_mutex);
+  }
+}
+
+void debuggerd_init(debuggerd_callbacks_t* callbacks) {
+  if (callbacks) {
+    g_callbacks = *callbacks;
+  }
+
+  void* thread_stack_allocation =
+    mmap(nullptr, PAGE_SIZE * 3, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+  if (thread_stack_allocation == MAP_FAILED) {
+    fatal("failed to allocate debuggerd thread stack");
+  }
+
+  char* stack = static_cast<char*>(thread_stack_allocation) + PAGE_SIZE;
+  if (mprotect(stack, PAGE_SIZE, PROT_READ | PROT_WRITE) != 0) {
+    fatal("failed to mprotect debuggerd thread stack");
+  }
+
+  // Stack grows negatively, set it to the last byte in the page...
+  stack = (stack + PAGE_SIZE - 1);
+  // and align it.
+  stack -= 15;
+  pseudothread_stack = stack;
+
+  struct sigaction action;
+  memset(&action, 0, sizeof(action));
+  sigfillset(&action.sa_mask);
+  action.sa_sigaction = debuggerd_signal_handler;
+  action.sa_flags = SA_RESTART | SA_SIGINFO;
+
+  // Use the alternate signal stack if available so we can catch stack overflows.
+  action.sa_flags |= SA_ONSTACK;
+
+  sigaction(SIGABRT, &action, nullptr);
+  sigaction(SIGBUS, &action, nullptr);
+  sigaction(SIGFPE, &action, nullptr);
+  sigaction(SIGILL, &action, nullptr);
+  sigaction(SIGSEGV, &action, nullptr);
+#if defined(SIGSTKFLT)
+  sigaction(SIGSTKFLT, &action, nullptr);
+#endif
+  sigaction(SIGTRAP, &action, nullptr);
+  sigaction(DEBUGGER_SIGNAL, &action, nullptr);
+}
diff --git a/debuggerd/include/debuggerd/client.h b/debuggerd/include/debuggerd/client.h
index aeb723b..91f143b 100644
--- a/debuggerd/include/debuggerd/client.h
+++ b/debuggerd/include/debuggerd/client.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 The Android Open Source Project
+ * 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.
@@ -16,44 +16,21 @@
 
 #pragma once
 
-#include <stdint.h>
+#include <stdbool.h>
 #include <sys/cdefs.h>
-#include <sys/types.h>
+#include <unistd.h>
 
-// On 32-bit devices, DEBUGGER_SOCKET_NAME is a 32-bit debuggerd.
-// On 64-bit devices, DEBUGGER_SOCKET_NAME is a 64-bit debuggerd.
-#define DEBUGGER_SOCKET_NAME "android:debuggerd"
+#include <android-base/unique_fd.h>
 
-// Used only on 64-bit devices for debuggerd32.
-#define DEBUGGER32_SOCKET_NAME "android:debuggerd32"
+enum DebuggerdDumpType {
+  kDebuggerdBacktrace,
+  kDebuggerdTombstone,
+};
 
-__BEGIN_DECLS
+// Trigger a dump of specified process to output_fd.
+// output_fd is *not* consumed, timeouts <= 0 will wait forever.
+bool debuggerd_trigger_dump(pid_t pid, android::base::unique_fd output_fd,
+                            enum DebuggerdDumpType dump_type, int timeout_ms);
 
-typedef enum {
-  // dump a crash
-  DEBUGGER_ACTION_CRASH,
-  // dump a tombstone file
-  DEBUGGER_ACTION_DUMP_TOMBSTONE,
-  // dump a backtrace only back to the socket
-  DEBUGGER_ACTION_DUMP_BACKTRACE,
-} debugger_action_t;
-
-// Make sure that all values have a fixed size so that this structure
-// is the same for 32 bit and 64 bit processes.
-typedef struct __attribute__((packed)) {
-  int32_t action;
-  pid_t tid;
-  pid_t ignore_tid;
-  uint64_t abort_msg_address;
-} debugger_msg_t;
-
-// These callbacks are called in a signal handler, and thus must be async signal safe.
-// If null, the callbacks will not be called.
-typedef struct {
-  struct abort_msg_t* (*get_abort_message)();
-  void (*post_dump)();
-} debuggerd_callbacks_t;
-
-void debuggerd_init(debuggerd_callbacks_t* callbacks);
-
-__END_DECLS
+int dump_backtrace_to_file(pid_t tid, int fd);
+int dump_backtrace_to_file_timeout(pid_t tid, int fd, int timeout_secs);
diff --git a/debuggerd/include/debuggerd/handler.h b/debuggerd/include/debuggerd/handler.h
new file mode 100644
index 0000000..302f4c2
--- /dev/null
+++ b/debuggerd/include/debuggerd/handler.h
@@ -0,0 +1,42 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+#include <signal.h>
+#include <stdint.h>
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+__BEGIN_DECLS
+
+// These callbacks are called in a signal handler, and thus must be async signal safe.
+// If null, the callbacks will not be called.
+typedef struct {
+  struct abort_msg_t* (*get_abort_message)();
+  void (*post_dump)();
+} debuggerd_callbacks_t;
+
+void debuggerd_init(debuggerd_callbacks_t* callbacks);
+
+// DEBUGGER_ACTION_DUMP_TOMBSTONE and DEBUGGER_ACTION_DUMP_BACKTRACE are both
+// triggered via DEBUGGER_SIGNAL. The debugger_action_t is sent via si_value
+// using sigqueue(2) or equivalent. If no si_value is specified (e.g. if the
+// signal is sent by kill(2)), the default behavior is to print the backtrace
+// to the log.
+#define DEBUGGER_SIGNAL (__SIGRTMIN + 3)
+
+__END_DECLS
diff --git a/debuggerd/include/debuggerd/protocol.h b/debuggerd/include/debuggerd/protocol.h
new file mode 100644
index 0000000..bb2ab0d
--- /dev/null
+++ b/debuggerd/include/debuggerd/protocol.h
@@ -0,0 +1,63 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+#include <stdint.h>
+
+// Sockets in the ANDROID_SOCKET_NAMESPACE_RESERVED namespace.
+// Both sockets are SOCK_SEQPACKET sockets, so no explicit length field is needed.
+constexpr char kTombstonedCrashSocketName[] = "tombstoned_crash";
+constexpr char kTombstonedInterceptSocketName[] = "tombstoned_intercept";
+
+enum class CrashPacketType : uint8_t {
+  // Initial request from crash_dump.
+  kDumpRequest = 0,
+
+  // Notification of a completed crash dump.
+  // Sent after a dump is completed and the process has been untraced, but
+  // before it has been resumed with SIGCONT.
+  kCompletedDump,
+
+  // Responses to kRequest.
+  // kPerformDump sends along an output fd via cmsg(3).
+  kPerformDump = 128,
+  kAbortDump,
+};
+
+struct DumpRequest {
+  int32_t pid;
+};
+
+// The full packet must always be written, regardless of whether the union is used.
+struct TombstonedCrashPacket {
+  CrashPacketType packet_type;
+  union {
+    DumpRequest dump_request;
+  } packet;
+};
+
+// Comes with a file descriptor via SCM_RIGHTS.
+// This packet should be sent before an actual dump happens.
+struct InterceptRequest {
+  int32_t pid;
+};
+
+// Sent either immediately upon failure, or when the intercept has been used.
+struct InterceptResponse {
+  uint8_t success;          // 0 or 1
+  char error_message[127];  // always null-terminated
+};
diff --git a/debuggerd/include/debuggerd/util.h b/debuggerd/include/debuggerd/util.h
new file mode 100644
index 0000000..6051714
--- /dev/null
+++ b/debuggerd/include/debuggerd/util.h
@@ -0,0 +1,46 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+#include <android-base/unique_fd.h>
+
+// *** WARNING ***
+// tombstoned's sockets are SOCK_SEQPACKET sockets.
+// Short reads are treated as errors and short writes are assumed to not happen.
+
+// Sends a packet with an attached fd.
+ssize_t send_fd(int sockfd, const void* _Nonnull data, size_t len, android::base::unique_fd fd);
+
+// Receives a packet and optionally, its attached fd.
+// If out_fd is non-null, packets can optionally have an attached fd.
+// If out_fd is null, received packets must not have an attached fd.
+//
+// Errors:
+//   EOVERFLOW: sockfd is SOCK_DGRAM or SOCK_SEQPACKET and buffer is too small.
+//              The first len bytes of the packet are stored in data, but the
+//              rest of the packet is dropped.
+//   ERANGE:    too many file descriptors were attached to the packet.
+//   ENOMSG:    not enough file descriptors were attached to the packet.
+//
+//   plus any errors returned by the underlying recvmsg.
+ssize_t recv_fd(int sockfd, void* _Nonnull data, size_t len,
+                android::base::unique_fd* _Nullable out_fd);
+
+bool Pipe(android::base::unique_fd* read, android::base::unique_fd* write);
diff --git a/debuggerd/arm/machine.cpp b/debuggerd/libdebuggerd/arm/machine.cpp
similarity index 100%
rename from debuggerd/arm/machine.cpp
rename to debuggerd/libdebuggerd/arm/machine.cpp
diff --git a/debuggerd/arm64/machine.cpp b/debuggerd/libdebuggerd/arm64/machine.cpp
similarity index 100%
rename from debuggerd/arm64/machine.cpp
rename to debuggerd/libdebuggerd/arm64/machine.cpp
diff --git a/debuggerd/backtrace.cpp b/debuggerd/libdebuggerd/backtrace.cpp
similarity index 100%
rename from debuggerd/backtrace.cpp
rename to debuggerd/libdebuggerd/backtrace.cpp
diff --git a/debuggerd/elf_utils.cpp b/debuggerd/libdebuggerd/elf_utils.cpp
similarity index 100%
rename from debuggerd/elf_utils.cpp
rename to debuggerd/libdebuggerd/elf_utils.cpp
diff --git a/debuggerd/backtrace.h b/debuggerd/libdebuggerd/include/backtrace.h
similarity index 100%
rename from debuggerd/backtrace.h
rename to debuggerd/libdebuggerd/include/backtrace.h
diff --git a/debuggerd/elf_utils.h b/debuggerd/libdebuggerd/include/elf_utils.h
similarity index 100%
rename from debuggerd/elf_utils.h
rename to debuggerd/libdebuggerd/include/elf_utils.h
diff --git a/debuggerd/machine.h b/debuggerd/libdebuggerd/include/machine.h
similarity index 100%
rename from debuggerd/machine.h
rename to debuggerd/libdebuggerd/include/machine.h
diff --git a/debuggerd/open_files_list.h b/debuggerd/libdebuggerd/include/open_files_list.h
similarity index 100%
rename from debuggerd/open_files_list.h
rename to debuggerd/libdebuggerd/include/open_files_list.h
diff --git a/debuggerd/tombstone.h b/debuggerd/libdebuggerd/include/tombstone.h
similarity index 97%
rename from debuggerd/tombstone.h
rename to debuggerd/libdebuggerd/include/tombstone.h
index 126f804..4ff24af 100644
--- a/debuggerd/tombstone.h
+++ b/debuggerd/libdebuggerd/include/tombstone.h
@@ -23,6 +23,8 @@
 #include <set>
 #include <string>
 
+#include "open_files_list.h"
+
 class BacktraceMap;
 
 /* Create and open a tombstone file for writing.
diff --git a/debuggerd/utility.h b/debuggerd/libdebuggerd/include/utility.h
similarity index 96%
rename from debuggerd/utility.h
rename to debuggerd/libdebuggerd/include/utility.h
index f7a3f73..bbc4546 100644
--- a/debuggerd/utility.h
+++ b/debuggerd/libdebuggerd/include/utility.h
@@ -18,6 +18,7 @@
 #ifndef _DEBUGGERD_UTILITY_H
 #define _DEBUGGERD_UTILITY_H
 
+#include <signal.h>
 #include <stdbool.h>
 #include <sys/types.h>
 
@@ -78,7 +79,7 @@
 void _LOG(log_t* log, logtype ltype, const char *fmt, ...)
         __attribute__ ((format(printf, 3, 4)));
 
-int wait_for_signal(pid_t tid);
+bool wait_for_signal(pid_t tid, siginfo_t* siginfo);
 
 void dump_memory(log_t* log, Backtrace* backtrace, uintptr_t addr, const char* fmt, ...);
 
diff --git a/debuggerd/mips/machine.cpp b/debuggerd/libdebuggerd/mips/machine.cpp
similarity index 100%
rename from debuggerd/mips/machine.cpp
rename to debuggerd/libdebuggerd/mips/machine.cpp
diff --git a/debuggerd/mips64/machine.cpp b/debuggerd/libdebuggerd/mips64/machine.cpp
similarity index 100%
rename from debuggerd/mips64/machine.cpp
rename to debuggerd/libdebuggerd/mips64/machine.cpp
diff --git a/debuggerd/open_files_list.cpp b/debuggerd/libdebuggerd/open_files_list.cpp
similarity index 100%
rename from debuggerd/open_files_list.cpp
rename to debuggerd/libdebuggerd/open_files_list.cpp
diff --git a/debuggerd/test/BacktraceMock.h b/debuggerd/libdebuggerd/test/BacktraceMock.h
similarity index 100%
rename from debuggerd/test/BacktraceMock.h
rename to debuggerd/libdebuggerd/test/BacktraceMock.h
diff --git a/debuggerd/test/dump_memory_test.cpp b/debuggerd/libdebuggerd/test/dump_memory_test.cpp
similarity index 100%
rename from debuggerd/test/dump_memory_test.cpp
rename to debuggerd/libdebuggerd/test/dump_memory_test.cpp
diff --git a/debuggerd/test/elf_fake.cpp b/debuggerd/libdebuggerd/test/elf_fake.cpp
similarity index 100%
rename from debuggerd/test/elf_fake.cpp
rename to debuggerd/libdebuggerd/test/elf_fake.cpp
diff --git a/debuggerd/test/elf_fake.h b/debuggerd/libdebuggerd/test/elf_fake.h
similarity index 100%
rename from debuggerd/test/elf_fake.h
rename to debuggerd/libdebuggerd/test/elf_fake.h
diff --git a/debuggerd/test/host_signal_fixup.h b/debuggerd/libdebuggerd/test/host_signal_fixup.h
similarity index 100%
rename from debuggerd/test/host_signal_fixup.h
rename to debuggerd/libdebuggerd/test/host_signal_fixup.h
diff --git a/debuggerd/test/log_fake.cpp b/debuggerd/libdebuggerd/test/log_fake.cpp
similarity index 100%
rename from debuggerd/test/log_fake.cpp
rename to debuggerd/libdebuggerd/test/log_fake.cpp
diff --git a/debuggerd/test/log_fake.h b/debuggerd/libdebuggerd/test/log_fake.h
similarity index 100%
rename from debuggerd/test/log_fake.h
rename to debuggerd/libdebuggerd/test/log_fake.h
diff --git a/debuggerd/test/open_files_list_test.cpp b/debuggerd/libdebuggerd/test/open_files_list_test.cpp
similarity index 100%
rename from debuggerd/test/open_files_list_test.cpp
rename to debuggerd/libdebuggerd/test/open_files_list_test.cpp
diff --git a/debuggerd/test/property_fake.cpp b/debuggerd/libdebuggerd/test/property_fake.cpp
similarity index 100%
rename from debuggerd/test/property_fake.cpp
rename to debuggerd/libdebuggerd/test/property_fake.cpp
diff --git a/debuggerd/test/ptrace_fake.cpp b/debuggerd/libdebuggerd/test/ptrace_fake.cpp
similarity index 100%
rename from debuggerd/test/ptrace_fake.cpp
rename to debuggerd/libdebuggerd/test/ptrace_fake.cpp
diff --git a/debuggerd/test/ptrace_fake.h b/debuggerd/libdebuggerd/test/ptrace_fake.h
similarity index 100%
rename from debuggerd/test/ptrace_fake.h
rename to debuggerd/libdebuggerd/test/ptrace_fake.h
diff --git a/debuggerd/test/sys/system_properties.h b/debuggerd/libdebuggerd/test/sys/system_properties.h
similarity index 100%
rename from debuggerd/test/sys/system_properties.h
rename to debuggerd/libdebuggerd/test/sys/system_properties.h
diff --git a/debuggerd/test/tombstone_test.cpp b/debuggerd/libdebuggerd/test/tombstone_test.cpp
similarity index 100%
rename from debuggerd/test/tombstone_test.cpp
rename to debuggerd/libdebuggerd/test/tombstone_test.cpp
diff --git a/debuggerd/tombstone.cpp b/debuggerd/libdebuggerd/tombstone.cpp
similarity index 98%
rename from debuggerd/tombstone.cpp
rename to debuggerd/libdebuggerd/tombstone.cpp
index e76edb9..01e9cf6 100644
--- a/debuggerd/tombstone.cpp
+++ b/debuggerd/libdebuggerd/tombstone.cpp
@@ -32,6 +32,7 @@
 #include <memory>
 #include <string>
 
+#include <android/log.h>
 #include <android-base/stringprintf.h>
 #include <backtrace/Backtrace.h>
 #include <backtrace/BacktraceMap.h>
@@ -39,9 +40,8 @@
 #include <log/log.h>
 #include <log/logprint.h>
 #include <private/android_filesystem_config.h>
-#include <private/android_logger.h>
 
-#include <selinux/android.h>
+#include "debuggerd/handler.h"
 
 #include "backtrace.h"
 #include "elf_utils.h"
@@ -86,6 +86,7 @@
     case SIGSTOP: return "SIGSTOP";
     case SIGSYS: return "SIGSYS";
     case SIGTRAP: return "SIGTRAP";
+    case DEBUGGER_SIGNAL: return "<debuggerd signal>";
     default: return "?";
   }
 }
@@ -625,7 +626,9 @@
                        const OpenFilesList& open_files, pid_t pid, pid_t tid,
                        const std::set<pid_t>& siblings, uintptr_t abort_msg_address) {
   // don't copy log messages to tombstone unless this is a dev device
-  bool want_logs = __android_log_is_debuggable();
+  char value[PROPERTY_VALUE_MAX];
+  property_get("ro.debuggable", value, "0");
+  bool want_logs = (value[0] == '1');
 
   _LOG(log, logtype::HEADER,
        "*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***\n");
diff --git a/debuggerd/utility.cpp b/debuggerd/libdebuggerd/utility.cpp
similarity index 95%
rename from debuggerd/utility.cpp
rename to debuggerd/libdebuggerd/utility.cpp
index 419d36c..57209aa 100644
--- a/debuggerd/utility.cpp
+++ b/debuggerd/libdebuggerd/utility.cpp
@@ -71,21 +71,25 @@
   }
 }
 
-int wait_for_signal(pid_t tid) {
+bool wait_for_signal(pid_t tid, siginfo_t* siginfo) {
   while (true) {
     int status;
     pid_t n = TEMP_FAILURE_RETRY(waitpid(tid, &status, __WALL));
     if (n == -1) {
       ALOGE("waitpid failed: tid %d, %s", tid, strerror(errno));
-      return -1;
+      return false;
     } else if (n == tid) {
       if (WIFSTOPPED(status)) {
-        return WSTOPSIG(status);
+        if (ptrace(PTRACE_GETSIGINFO, tid, nullptr, siginfo) != 0) {
+          ALOGE("PTRACE_GETSIGINFO failed: %s", strerror(errno));
+          return false;
+        }
+        return true;
       } else {
         ALOGE("unexpected waitpid response: n=%d, status=%08x\n", n, status);
         // This is the only circumstance under which we can allow a detach
         // to fail with ESRCH, which indicates the tid has exited.
-        return -1;
+        return false;
       }
     }
   }
diff --git a/debuggerd/x86/machine.cpp b/debuggerd/libdebuggerd/x86/machine.cpp
similarity index 100%
rename from debuggerd/x86/machine.cpp
rename to debuggerd/libdebuggerd/x86/machine.cpp
diff --git a/debuggerd/x86_64/machine.cpp b/debuggerd/libdebuggerd/x86_64/machine.cpp
similarity index 100%
rename from debuggerd/x86_64/machine.cpp
rename to debuggerd/libdebuggerd/x86_64/machine.cpp
diff --git a/debuggerd/signal_sender.h b/debuggerd/signal_sender.h
deleted file mode 100644
index 0443272..0000000
--- a/debuggerd/signal_sender.h
+++ /dev/null
@@ -1,30 +0,0 @@
-/*
- * Copyright (C) 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.
- */
-
-#ifndef _DEBUGGERD_SIGNAL_SENDER_H
-#define _DEBUGGERD_SIGNAL_SENDER_H
-
-#include <sys/types.h>
-
-bool start_signal_sender();
-bool stop_signal_sender();
-
-// Sends a signal to a target process or thread.
-// If tid is greater than zero, this performs tgkill(pid, tid, signal).
-// Otherwise, it performs kill(pid, signal).
-bool send_signal(pid_t pid, pid_t tid, int signal);
-
-#endif
diff --git a/debuggerd/test/selinux/android.h b/debuggerd/test/selinux/android.h
deleted file mode 100644
index abed087..0000000
--- a/debuggerd/test/selinux/android.h
+++ /dev/null
@@ -1,17 +0,0 @@
-/*
- * Copyright (C) 2015 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.
- */
-
-extern "C" int selinux_android_restorecon(const char*, unsigned int);
diff --git a/debuggerd/test/selinux_fake.cpp b/debuggerd/test/selinux_fake.cpp
deleted file mode 100644
index acdd0a9..0000000
--- a/debuggerd/test/selinux_fake.cpp
+++ /dev/null
@@ -1,19 +0,0 @@
-/*
- * Copyright (C) 2015 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.
- */
-
-extern "C" int selinux_android_restorecon(const char*, unsigned int) {
-  return 0;
-}
diff --git a/debuggerd/tombstoned/intercept_manager.cpp b/debuggerd/tombstoned/intercept_manager.cpp
new file mode 100644
index 0000000..789260d
--- /dev/null
+++ b/debuggerd/tombstoned/intercept_manager.cpp
@@ -0,0 +1,182 @@
+/*
+ * 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 "intercept_manager.h"
+
+#include <inttypes.h>
+#include <sys/types.h>
+
+#include <unordered_map>
+
+#include <event2/event.h>
+#include <event2/listener.h>
+
+#include <android-base/logging.h>
+#include <android-base/unique_fd.h>
+#include <cutils/sockets.h>
+
+#include "debuggerd/protocol.h"
+#include "debuggerd/util.h"
+
+using android::base::unique_fd;
+
+static void intercept_close_cb(evutil_socket_t sockfd, short event, void* arg) {
+  auto intercept = reinterpret_cast<Intercept*>(arg);
+  InterceptManager* intercept_manager = intercept->intercept_manager;
+
+  CHECK_EQ(sockfd, intercept->sockfd.get());
+
+  // If we can read, either we received unexpected data from the other side, or the other side
+  // closed their end of the socket. Either way, kill the intercept.
+
+  // Ownership of intercept differs based on whether we've registered it with InterceptManager.
+  if (!intercept->registered) {
+    delete intercept;
+  } else {
+    auto it = intercept_manager->intercepts.find(intercept->intercept_pid);
+    if (it == intercept_manager->intercepts.end()) {
+      LOG(FATAL) << "intercept close callback called after intercept was already removed?";
+    }
+    if (it->second.get() != intercept) {
+      LOG(FATAL) << "intercept close callback has different Intercept from InterceptManager?";
+    }
+
+    const char* reason;
+    if ((event & EV_TIMEOUT) != 0) {
+      reason = "due to timeout";
+    } else {
+      reason = "due to input";
+    }
+
+    LOG(INFO) << "intercept for pid " << intercept->intercept_pid << " terminated " << reason;
+    intercept_manager->intercepts.erase(it);
+  }
+}
+
+static void intercept_request_cb(evutil_socket_t sockfd, short ev, void* arg) {
+  auto intercept = reinterpret_cast<Intercept*>(arg);
+  InterceptManager* intercept_manager = intercept->intercept_manager;
+
+  CHECK_EQ(sockfd, intercept->sockfd.get());
+
+  if ((ev & EV_TIMEOUT) != 0) {
+    LOG(WARNING) << "tombstoned didn't receive InterceptRequest before timeout";
+    goto fail;
+  } else if ((ev & EV_READ) == 0) {
+    LOG(WARNING) << "tombstoned received unexpected event on intercept socket";
+    goto fail;
+  }
+
+  {
+    unique_fd rcv_fd;
+    InterceptRequest intercept_request;
+    ssize_t result = recv_fd(sockfd, &intercept_request, sizeof(intercept_request), &rcv_fd);
+
+    if (result == -1) {
+      PLOG(WARNING) << "failed to read from intercept socket";
+      goto fail;
+    } else if (result != sizeof(intercept_request)) {
+      LOG(WARNING) << "intercept socket received short read of length " << result << " (expected "
+                   << sizeof(intercept_request) << ")";
+      goto fail;
+    }
+
+    // Move the received FD to the upper half, in order to more easily notice FD leaks.
+    int moved_fd = fcntl(rcv_fd.get(), F_DUPFD, 512);
+    if (moved_fd == -1) {
+      LOG(WARNING) << "failed to move received fd (" << rcv_fd.get() << ")";
+      goto fail;
+    }
+    rcv_fd.reset(moved_fd);
+
+    // We trust the other side, so only do minimal validity checking.
+    if (intercept_request.pid <= 0 || intercept_request.pid > std::numeric_limits<pid_t>::max()) {
+      InterceptResponse response = {};
+      snprintf(response.error_message, sizeof(response.error_message), "invalid pid %" PRId32,
+               intercept_request.pid);
+      TEMP_FAILURE_RETRY(write(sockfd, &response, sizeof(response)));
+      goto fail;
+    }
+
+    intercept->intercept_pid = intercept_request.pid;
+
+    // Register the intercept with the InterceptManager.
+    if (intercept_manager->intercepts.count(intercept_request.pid) > 0) {
+      InterceptResponse response = {};
+      snprintf(response.error_message, sizeof(response.error_message),
+               "pid %" PRId32 " already intercepted", intercept_request.pid);
+      TEMP_FAILURE_RETRY(write(sockfd, &response, sizeof(response)));
+      LOG(WARNING) << response.error_message;
+      goto fail;
+    }
+
+    intercept->output_fd = std::move(rcv_fd);
+    intercept_manager->intercepts[intercept_request.pid] = std::unique_ptr<Intercept>(intercept);
+    intercept->registered = true;
+
+    LOG(INFO) << "tombstoned registered intercept for pid " << intercept_request.pid;
+
+    // Register a different read event on the socket so that we can remove intercepts if the socket
+    // closes (e.g. if a user CTRL-C's the process that requested the intercept).
+    event_assign(intercept->intercept_event, intercept_manager->base, sockfd, EV_READ | EV_TIMEOUT,
+                 intercept_close_cb, arg);
+
+    struct timeval timeout = { .tv_sec = 10, .tv_usec = 0 };
+    event_add(intercept->intercept_event, &timeout);
+  }
+
+  return;
+
+fail:
+  delete intercept;
+}
+
+static void intercept_accept_cb(evconnlistener* listener, evutil_socket_t sockfd, sockaddr*, int,
+                                void* arg) {
+  Intercept* intercept = new Intercept();
+  intercept->intercept_manager = static_cast<InterceptManager*>(arg);
+  intercept->sockfd.reset(sockfd);
+
+  struct timeval timeout = { 1, 0 };
+  event_base* base = evconnlistener_get_base(listener);
+  event* intercept_event =
+    event_new(base, sockfd, EV_TIMEOUT | EV_READ, intercept_request_cb, intercept);
+  intercept->intercept_event = intercept_event;
+  event_add(intercept_event, &timeout);
+}
+
+InterceptManager::InterceptManager(event_base* base, int intercept_socket) : base(base) {
+  this->listener = evconnlistener_new(base, intercept_accept_cb, this, -1, LEV_OPT_CLOSE_ON_FREE,
+                                      intercept_socket);
+}
+
+bool InterceptManager::GetIntercept(pid_t pid, android::base::unique_fd* out_fd) {
+  auto it = this->intercepts.find(pid);
+  if (it == this->intercepts.end()) {
+    return false;
+  }
+
+  auto intercept = std::move(it->second);
+  this->intercepts.erase(it);
+
+  LOG(INFO) << "found intercept fd " << intercept->output_fd.get() << " for pid " << pid;
+  InterceptResponse response = {};
+  response.success = 1;
+  TEMP_FAILURE_RETRY(write(intercept->sockfd, &response, sizeof(response)));
+  *out_fd = std::move(intercept->output_fd);
+
+  return true;
+}
diff --git a/debuggerd/tombstoned/intercept_manager.h b/debuggerd/tombstoned/intercept_manager.h
new file mode 100644
index 0000000..cb5db62
--- /dev/null
+++ b/debuggerd/tombstoned/intercept_manager.h
@@ -0,0 +1,54 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+#include <sys/types.h>
+
+#include <unordered_map>
+
+#include <event2/event.h>
+#include <event2/listener.h>
+
+#include <android-base/unique_fd.h>
+
+struct InterceptManager;
+
+struct Intercept {
+  ~Intercept() {
+    event_free(intercept_event);
+  }
+
+  InterceptManager* intercept_manager = nullptr;
+  event* intercept_event = nullptr;
+  android::base::unique_fd sockfd;
+
+  pid_t intercept_pid = -1;
+  android::base::unique_fd output_fd;
+  bool registered = false;
+};
+
+struct InterceptManager {
+  event_base* base;
+  std::unordered_map<pid_t, std::unique_ptr<Intercept>> intercepts;
+  evconnlistener* listener = nullptr;
+
+  InterceptManager(event_base* _Nonnull base, int intercept_socket);
+  InterceptManager(InterceptManager& copy) = delete;
+  InterceptManager(InterceptManager&& move) = delete;
+
+  bool GetIntercept(pid_t pid, android::base::unique_fd* out_fd);
+};
diff --git a/debuggerd/tombstoned/tombstoned.cpp b/debuggerd/tombstoned/tombstoned.cpp
new file mode 100644
index 0000000..3c1dcaf
--- /dev/null
+++ b/debuggerd/tombstoned/tombstoned.cpp
@@ -0,0 +1,283 @@
+/*
+ * 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 <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <array>
+#include <deque>
+#include <unordered_map>
+
+#include <event2/event.h>
+#include <event2/listener.h>
+#include <event2/thread.h>
+
+#include <android-base/logging.h>
+#include <android-base/stringprintf.h>
+#include <android-base/unique_fd.h>
+#include <cutils/sockets.h>
+
+#include "debuggerd/protocol.h"
+#include "debuggerd/util.h"
+
+#include "intercept_manager.h"
+
+using android::base::StringPrintf;
+using android::base::unique_fd;
+
+static InterceptManager* intercept_manager;
+
+enum CrashStatus {
+  kCrashStatusRunning,
+  kCrashStatusQueued,
+};
+
+// Ownership of Crash is a bit messy.
+// It's either owned by an active event that must have a timeout, or owned by
+// queued_requests, in the case that multiple crashes come in at the same time.
+struct Crash {
+  ~Crash() {
+    event_free(crash_event);
+  }
+
+  unique_fd crash_fd;
+  pid_t crash_pid;
+  event* crash_event = nullptr;
+};
+
+static constexpr char kTombstoneDirectory[] = "/data/tombstones/";
+static constexpr size_t kTombstoneCount = 10;
+static int tombstone_directory_fd = -1;
+static int next_tombstone = 0;
+
+static constexpr size_t kMaxConcurrentDumps = 1;
+static size_t num_concurrent_dumps = 0;
+
+static std::deque<Crash*> queued_requests;
+
+// Forward declare the callbacks so they can be placed in a sensible order.
+static void crash_accept_cb(evconnlistener* listener, evutil_socket_t sockfd, sockaddr*, int, void*);
+static void crash_request_cb(evutil_socket_t sockfd, short ev, void* arg);
+static void crash_completed_cb(evutil_socket_t sockfd, short ev, void* arg);
+
+static void find_oldest_tombstone() {
+  size_t oldest_tombstone = 0;
+  time_t oldest_time = std::numeric_limits<time_t>::max();
+
+  for (size_t i = 0; i < kTombstoneCount; ++i) {
+    std::string path = android::base::StringPrintf("%stombstone_%02zu", kTombstoneDirectory, i);
+    struct stat st;
+    if (stat(path.c_str(), &st) != 0) {
+      PLOG(ERROR) << "failed to stat " << path;
+    }
+
+    if (st.st_mtime < oldest_time) {
+      oldest_tombstone = i;
+      oldest_time = st.st_mtime;
+    }
+  }
+
+  next_tombstone = oldest_tombstone;
+}
+
+static unique_fd get_tombstone_fd() {
+  // If kMaxConcurrentDumps is greater than 1, then theoretically the same
+  // filename could be handed out to multiple processes. Unlink and create the
+  // file, instead of using O_TRUNC, to avoid two processes interleaving their
+  // output.
+  unique_fd result;
+  char buf[PATH_MAX];
+  snprintf(buf, sizeof(buf), "tombstone_%02d", next_tombstone);
+  if (unlinkat(tombstone_directory_fd, buf, 0) != 0 && errno != ENOENT) {
+    PLOG(FATAL) << "failed to unlink tombstone at " << kTombstoneDirectory << buf;
+  }
+
+  result.reset(
+    openat(tombstone_directory_fd, buf, O_CREAT | O_EXCL | O_WRONLY | O_APPEND, O_CLOEXEC, 0700));
+  if (result == -1) {
+    PLOG(FATAL) << "failed to create tombstone at " << kTombstoneDirectory << buf;
+  }
+
+  next_tombstone = (next_tombstone + 1) % kTombstoneCount;
+  return result;
+}
+
+static void dequeue_request(Crash* crash) {
+  ++num_concurrent_dumps;
+
+  unique_fd output_fd;
+  if (!intercept_manager->GetIntercept(crash->crash_pid, &output_fd)) {
+    output_fd = get_tombstone_fd();
+  }
+
+  TombstonedCrashPacket response = {
+    .packet_type = CrashPacketType::kPerformDump
+  };
+  ssize_t rc = send_fd(crash->crash_fd, &response, sizeof(response), std::move(output_fd));
+  if (rc == -1) {
+    PLOG(WARNING) << "failed to send response to CrashRequest";
+    goto fail;
+  } else if (rc != sizeof(response)) {
+    PLOG(WARNING) << "crash socket write returned short";
+    goto fail;
+  } else {
+    // TODO: Make this configurable by the interceptor?
+    struct timeval timeout = { 10, 0 };
+
+    event_base* base = event_get_base(crash->crash_event);
+    event_assign(crash->crash_event, base, crash->crash_fd, EV_TIMEOUT | EV_READ,
+                 crash_completed_cb, crash);
+    event_add(crash->crash_event, &timeout);
+  }
+  return;
+
+fail:
+  delete crash;
+}
+
+static void crash_accept_cb(evconnlistener* listener, evutil_socket_t sockfd, sockaddr*, int,
+                            void*) {
+  event_base* base = evconnlistener_get_base(listener);
+  Crash* crash = new Crash();
+
+  struct timeval timeout = { 1, 0 };
+  event* crash_event = event_new(base, sockfd, EV_TIMEOUT | EV_READ, crash_request_cb, crash);
+  crash->crash_fd.reset(sockfd);
+  crash->crash_event = crash_event;
+  event_add(crash_event, &timeout);
+}
+
+static void crash_request_cb(evutil_socket_t sockfd, short ev, void* arg) {
+  ssize_t rc;
+  Crash* crash = static_cast<Crash*>(arg);
+  TombstonedCrashPacket request = {};
+
+  if ((ev & EV_TIMEOUT) != 0) {
+    LOG(WARNING) << "crash request timed out";
+    goto fail;
+  } else if ((ev & EV_READ) == 0) {
+    LOG(WARNING) << "tombstoned received unexpected event from crash socket";
+    goto fail;
+  }
+
+  rc = TEMP_FAILURE_RETRY(read(sockfd, &request, sizeof(request)));
+  if (rc == -1) {
+    PLOG(WARNING) << "failed to read from crash socket";
+    goto fail;
+  } else if (rc != sizeof(request)) {
+    LOG(WARNING) << "crash socket received short read of length " << rc << " (expected "
+                 << sizeof(request) << ")";
+    goto fail;
+  }
+
+  if (request.packet_type != CrashPacketType::kDumpRequest) {
+    LOG(WARNING) << "unexpected crash packet type, expected kDumpRequest, received  "
+                 << StringPrintf("%#2hhX", request.packet_type);
+    goto fail;
+  }
+
+  crash->crash_pid = request.packet.dump_request.pid;
+  LOG(INFO) << "received crash request for pid " << crash->crash_pid;
+
+  if (num_concurrent_dumps == kMaxConcurrentDumps) {
+    LOG(INFO) << "enqueueing crash request for pid " << crash->crash_pid;
+    queued_requests.push_back(crash);
+  } else {
+    dequeue_request(crash);
+  }
+
+  return;
+
+fail:
+  delete crash;
+}
+
+static void crash_completed_cb(evutil_socket_t sockfd, short ev, void* arg) {
+  ssize_t rc;
+  Crash* crash = static_cast<Crash*>(arg);
+  TombstonedCrashPacket request = {};
+
+  --num_concurrent_dumps;
+
+  if ((ev & EV_READ) == 0) {
+    goto fail;
+  }
+
+  rc = TEMP_FAILURE_RETRY(read(sockfd, &request, sizeof(request)));
+  if (rc == -1) {
+    PLOG(WARNING) << "failed to read from crash socket";
+    goto fail;
+  } else if (rc != sizeof(request)) {
+    LOG(WARNING) << "crash socket received short read of length " << rc << " (expected "
+                 << sizeof(request) << ")";
+    goto fail;
+  }
+
+  if (request.packet_type != CrashPacketType::kCompletedDump) {
+    LOG(WARNING) << "unexpected crash packet type, expected kCompletedDump, received "
+                 << uint32_t(request.packet_type);
+    goto fail;
+  }
+
+fail:
+  delete crash;
+
+  // If there's something queued up, let them proceed.
+  if (!queued_requests.empty()) {
+    Crash* next_crash = queued_requests.front();
+    queued_requests.pop_front();
+    dequeue_request(next_crash);
+  }
+}
+
+int main(int, char* []) {
+  tombstone_directory_fd = open(kTombstoneDirectory, O_DIRECTORY | O_RDONLY | O_CLOEXEC);
+  if (tombstone_directory_fd == -1) {
+    PLOG(FATAL) << "failed to open tombstone directory";
+  }
+
+  find_oldest_tombstone();
+
+  int intercept_socket = android_get_control_socket(kTombstonedInterceptSocketName);
+  int crash_socket = android_get_control_socket(kTombstonedCrashSocketName);
+
+  if (intercept_socket == -1 || crash_socket == -1) {
+    PLOG(FATAL) << "failed to get socket from init";
+  }
+
+  evutil_make_socket_nonblocking(intercept_socket);
+  evutil_make_socket_nonblocking(crash_socket);
+
+  event_base* base = event_base_new();
+  if (!base) {
+    LOG(FATAL) << "failed to create event_base";
+  }
+
+  intercept_manager = new InterceptManager(base, intercept_socket);
+
+  evconnlistener* listener =
+    evconnlistener_new(base, crash_accept_cb, nullptr, -1, LEV_OPT_CLOSE_ON_FREE, crash_socket);
+  if (!listener) {
+    LOG(FATAL) << "failed to create evconnlistener";
+  }
+
+  LOG(INFO) << "tombstoned successfully initialized";
+  event_base_dispatch(base);
+}
diff --git a/debuggerd/tombstoned/tombstoned.rc b/debuggerd/tombstoned/tombstoned.rc
new file mode 100644
index 0000000..3aacf33
--- /dev/null
+++ b/debuggerd/tombstoned/tombstoned.rc
@@ -0,0 +1,9 @@
+service tombstoned /system/bin/tombstoned
+    class core
+
+    user tombstoned
+    group system
+
+    socket tombstoned_crash seqpacket 0666 system system
+    socket tombstoned_intercept seqpacket 0666 system system
+    writepid /dev/cpuset/system-background/tasks
diff --git a/debuggerd/util.cpp b/debuggerd/util.cpp
new file mode 100644
index 0000000..738abdf
--- /dev/null
+++ b/debuggerd/util.cpp
@@ -0,0 +1,96 @@
+/*
+ * 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 "debuggerd/util.h"
+
+#include <sys/socket.h>
+
+#include <utility>
+
+#include <android-base/unique_fd.h>
+#include <cutils/sockets.h>
+
+ssize_t send_fd(int sockfd, const void* data, size_t len, android::base::unique_fd fd) {
+  char cmsg_buf[CMSG_SPACE(sizeof(int))];
+
+  iovec iov = { .iov_base = const_cast<void*>(data), .iov_len = len };
+  msghdr msg = {
+    .msg_iov = &iov, .msg_iovlen = 1, .msg_control = cmsg_buf, .msg_controllen = sizeof(cmsg_buf),
+  };
+  auto cmsg = CMSG_FIRSTHDR(&msg);
+  cmsg->cmsg_level = SOL_SOCKET;
+  cmsg->cmsg_type = SCM_RIGHTS;
+  cmsg->cmsg_len = CMSG_LEN(sizeof(int));
+  *reinterpret_cast<int*>(CMSG_DATA(cmsg)) = fd.get();
+
+  return TEMP_FAILURE_RETRY(sendmsg(sockfd, &msg, 0));
+}
+
+ssize_t recv_fd(int sockfd, void* _Nonnull data, size_t len,
+                android::base::unique_fd* _Nullable out_fd) {
+  char cmsg_buf[CMSG_SPACE(sizeof(int))];
+
+  iovec iov = { .iov_base = const_cast<void*>(data), .iov_len = len };
+  msghdr msg = {
+    .msg_iov = &iov,
+    .msg_iovlen = 1,
+    .msg_control = cmsg_buf,
+    .msg_controllen = sizeof(cmsg_buf),
+    .msg_flags = 0,
+  };
+  auto cmsg = CMSG_FIRSTHDR(&msg);
+  cmsg->cmsg_level = SOL_SOCKET;
+  cmsg->cmsg_type = SCM_RIGHTS;
+  cmsg->cmsg_len = CMSG_LEN(sizeof(int));
+
+  ssize_t result = TEMP_FAILURE_RETRY(recvmsg(sockfd, &msg, 0));
+  if (result == -1) {
+    return -1;
+  }
+
+  android::base::unique_fd fd;
+  bool received_fd = msg.msg_controllen == sizeof(cmsg_buf);
+  if (received_fd) {
+    fd.reset(*reinterpret_cast<int*>(CMSG_DATA(cmsg)));
+  }
+
+  if ((msg.msg_flags & MSG_TRUNC) != 0) {
+    errno = EFBIG;
+    return -1;
+  } else if ((msg.msg_flags & MSG_CTRUNC) != 0) {
+    errno = ERANGE;
+    return -1;
+  }
+
+  if (out_fd) {
+    *out_fd = std::move(fd);
+  } else if (received_fd) {
+    errno = ERANGE;
+    return -1;
+  }
+
+  return result;
+}
+
+bool Pipe(android::base::unique_fd* read, android::base::unique_fd* write) {
+  int pipefds[2];
+  if (pipe(pipefds) != 0) {
+    return false;
+  }
+  read->reset(pipefds[0]);
+  write->reset(pipefds[1]);
+  return true;
+}