Next phase of the move, reformat use C++ features.

Use the libbacktrace C++ interface instead of the C interface in debuggerd.

Reformat the debuggerd code to be closer to Google C++ style.

Fix all debuggerd casts to be C++ casts.

Add a frame number to the frame data structure for ease of formatting and
add another FormatFrameData function.

Change the format_test to use the new FormatFrameData function.

Modify all of the backtrace_test to use the C++ interface.

Change-Id: I10e1610861acf7f4a3ad53276b74971cfbfda464

1 files changed, 422 insertions, 447 deletions

diff --git a/debuggerd/debuggerd.cpp b/debuggerd/debuggerd.cpp
index a9f59c88c..de8ba9d4e 100644
--- a/debuggerd/debuggerd.cpp
+++ b/debuggerd/debuggerd.cpp
@@ -1,19 +1,18 @@
-/* system/debuggerd/debuggerd.c
-**
-** Copyright 2006, 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.
-*/
+/*
+ * Copyright 2006, 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 <stdio.h>
 #include <errno.h>
@@ -38,8 +37,6 @@
 #include <cutils/properties.h>
 #include <cutils/debugger.h>
 
-#include <corkscrew/backtrace.h>
-
 #include <linux/input.h>
 
 #include <private/android_filesystem_config.h>
@@ -50,490 +47,468 @@
 #include "utility.h"
 
 typedef struct {
-    debugger_action_t action;
-    pid_t pid, tid;
-    uid_t uid, gid;
-    uintptr_t abort_msg_address;
+  debugger_action_t action;
+  pid_t pid, tid;
+  uid_t uid, gid;
+  uintptr_t abort_msg_address;
 } debugger_request_t;
 
-static int
-write_string(const char* file, const char* string)
-{
-    int len;
-    int fd;
-    ssize_t amt;
-    fd = open(file, O_RDWR);
-    len = strlen(string);
-    if (fd < 0)
-        return -errno;
-    amt = write(fd, string, len);
-    close(fd);
-    return amt >= 0 ? 0 : -errno;
+static int write_string(const char* file, const char* string) {
+  int len;
+  int fd;
+  ssize_t amt;
+  fd = open(file, O_RDWR);
+  len = strlen(string);
+  if (fd < 0)
+    return -errno;
+  amt = write(fd, string, len);
+  close(fd);
+  return amt >= 0 ? 0 : -errno;
 }
 
-static
-void init_debug_led(void)
-{
-    // trout leds
-    write_string("/sys/class/leds/red/brightness", "0");
-    write_string("/sys/class/leds/green/brightness", "0");
-    write_string("/sys/class/leds/blue/brightness", "0");
-    write_string("/sys/class/leds/red/device/blink", "0");
-    // sardine leds
-    write_string("/sys/class/leds/left/cadence", "0,0");
+static void init_debug_led() {
+  // trout leds
+  write_string("/sys/class/leds/red/brightness", "0");
+  write_string("/sys/class/leds/green/brightness", "0");
+  write_string("/sys/class/leds/blue/brightness", "0");
+  write_string("/sys/class/leds/red/device/blink", "0");
+  // sardine leds
+  write_string("/sys/class/leds/left/cadence", "0,0");
 }
 
-static
-void enable_debug_led(void)
-{
-    // trout leds
-    write_string("/sys/class/leds/red/brightness", "255");
-    // sardine leds
-    write_string("/sys/class/leds/left/cadence", "1,0");
+static void enable_debug_led() {
+  // trout leds
+  write_string("/sys/class/leds/red/brightness", "255");
+  // sardine leds
+  write_string("/sys/class/leds/left/cadence", "1,0");
 }
 
-static
-void disable_debug_led(void)
-{
-    // trout leds
-    write_string("/sys/class/leds/red/brightness", "0");
-    // sardine leds
-    write_string("/sys/class/leds/left/cadence", "0,0");
+static void disable_debug_led() {
+  // trout leds
+  write_string("/sys/class/leds/red/brightness", "0");
+  // sardine leds
+  write_string("/sys/class/leds/left/cadence", "0,0");
 }
 
 static void wait_for_user_action(pid_t pid) {
-    /* First log a helpful message */
-    LOG(    "********************************************************\n"
-            "* Process %d has been suspended while crashing.  To\n"
-            "* attach gdbserver for a gdb connection on port 5039\n"
-            "* and start gdbclient:\n"
-            "*\n"
-            "*     gdbclient app_process :5039 %d\n"
-            "*\n"
-            "* Wait for gdb to start, then press HOME or VOLUME DOWN key\n"
-            "* to let the process continue crashing.\n"
-            "********************************************************\n",
-            pid, pid);
-
-    /* wait for HOME or VOLUME DOWN key */
-    if (init_getevent() == 0) {
-        int ms = 1200 / 10;
-        int dit = 1;
-        int dah = 3*dit;
-        int _       = -dit;
-        int ___     = 3*_;
-        int _______ = 7*_;
-        const int codes[] = {
-           dit,_,dit,_,dit,___,dah,_,dah,_,dah,___,dit,_,dit,_,dit,_______
-        };
-        size_t s = 0;
-        struct input_event e;
-        bool done = false;
-        init_debug_led();
-        enable_debug_led();
-        do {
-            int timeout = abs(codes[s]) * ms;
-            int res = get_event(&e, timeout);
-            if (res == 0) {
-                if (e.type == EV_KEY
-                        && (e.code == KEY_HOME || e.code == KEY_VOLUMEDOWN)
-                        && e.value == 0) {
-                    done = true;
-                }
-            } else if (res == 1) {
-                if (++s >= sizeof(codes)/sizeof(*codes))
-                    s = 0;
-                if (codes[s] > 0) {
-                    enable_debug_led();
-                } else {
-                    disable_debug_led();
-                }
-            }
-        } while (!done);
-        uninit_getevent();
-    }
-
-    /* don't forget to turn debug led off */
-    disable_debug_led();
-    LOG("debuggerd resuming process %d", pid);
+  // First log a helpful message
+  LOG(    "********************************************************\n"
+          "* Process %d has been suspended while crashing.  To\n"
+          "* attach gdbserver for a gdb connection on port 5039\n"
+          "* and start gdbclient:\n"
+          "*\n"
+          "*     gdbclient app_process :5039 %d\n"
+          "*\n"
+          "* Wait for gdb to start, then press HOME or VOLUME DOWN key\n"
+          "* to let the process continue crashing.\n"
+          "********************************************************\n",
+          pid, pid);
+
+  // wait for HOME or VOLUME DOWN key
+  if (init_getevent() == 0) {
+    int ms = 1200 / 10;
+    int dit = 1;
+    int dah = 3*dit;
+    int _       = -dit;
+    int ___     = 3*_;
+    int _______ = 7*_;
+    const int codes[] = {
+      dit,_,dit,_,dit,___,dah,_,dah,_,dah,___,dit,_,dit,_,dit,_______
+    };
+    size_t s = 0;
+    struct input_event e;
+    bool done = false;
+    init_debug_led();
+    enable_debug_led();
+    do {
+      int timeout = abs(codes[s]) * ms;
+      int res = get_event(&e, timeout);
+      if (res == 0) {
+        if (e.type == EV_KEY
+            && (e.code == KEY_HOME || e.code == KEY_VOLUMEDOWN)
+            && e.value == 0) {
+          done = true;
+        }
+      } else if (res == 1) {
+        if (++s >= sizeof(codes)/sizeof(*codes))
+          s = 0;
+        if (codes[s] > 0) {
+          enable_debug_led();
+        } else {
+          disable_debug_led();
+        }
+      }
+    } while (!done);
+    uninit_getevent();
+  }
+
+  // don't forget to turn debug led off
+  disable_debug_led();
+  LOG("debuggerd resuming process %d", 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);
-
-    FILE* fp = fopen(path, "r");
-    if (!fp) {
-        return -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;
-        }
+  char path[64];
+  snprintf(path, sizeof(path), "/proc/%d/status", tid);
+
+  FILE* fp = fopen(path, "r");
+  if (!fp) {
+    return -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;
+  }
+  fclose(fp);
+  return fields == 7 ? 0 : -1;
 }
 
 static int read_request(int fd, debugger_request_t* out_request) {
-    struct ucred cr;
-    int len = sizeof(cr);
-    int status = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cr, &len);
-    if (status != 0) {
-        LOG("cannot get credentials\n");
-        return -1;
-    }
-
-    XLOG("reading tid\n");
-    fcntl(fd, F_SETFL, O_NONBLOCK);
-
-    struct 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) {
-        LOG("timed out reading tid (from pid=%d uid=%d)\n", cr.pid, cr.uid);
-        return -1;
+  struct ucred cr;
+  int len = sizeof(cr);
+  int status = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cr, &len);
+  if (status != 0) {
+    LOG("cannot get credentials\n");
+    return -1;
+  }
+
+  XLOG("reading tid\n");
+  fcntl(fd, F_SETFL, O_NONBLOCK);
+
+  struct 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) {
+    LOG("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) {
+    LOG("read failure? %s (pid=%d uid=%d)\n", strerror(errno), cr.pid, cr.uid);
+    return -1;
+  }
+  if (status == sizeof(debugger_msg_t)) {
+    XLOG("crash request of size %d abort_msg_address=%#08x\n", status, msg.abort_msg_address);
+  } else {
+    LOG("invalid crash request of size %d (from pid=%d uid=%d)\n", status, cr.pid, cr.uid);
+    return -1;
+  }
+
+  out_request->action = msg.action;
+  out_request->tid = msg.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.
+    char buf[64];
+    struct stat s;
+    snprintf(buf, sizeof buf, "/proc/%d/task/%d", out_request->pid, out_request->tid);
+    if (stat(buf, &s)) {
+      LOG("tid %d does not exist in pid %d. ignoring debug request\n",
+          out_request->tid, out_request->pid);
+      return -1;
     }
-
-    debugger_msg_t msg;
-    memset(&msg, 0, sizeof(msg));
-    status = TEMP_FAILURE_RETRY(read(fd, &msg, sizeof(msg)));
-    if (status < 0) {
-        LOG("read failure? %s (pid=%d uid=%d)\n",
-            strerror(errno), cr.pid, cr.uid);
-        return -1;
-    }
-    if (status == sizeof(debugger_msg_t)) {
-        XLOG("crash request of size %d abort_msg_address=%#08x\n", status, msg.abort_msg_address);
-    } else {
-        LOG("invalid crash request of size %d (from pid=%d uid=%d)\n",
-            status, cr.pid, cr.uid);
-        return -1;
-    }
-
-    out_request->action = msg.action;
-    out_request->tid = msg.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. */
-        char buf[64];
-        struct stat s;
-        snprintf(buf, sizeof buf, "/proc/%d/task/%d", out_request->pid, out_request->tid);
-        if(stat(buf, &s)) {
-            LOG("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
+  } 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) {
-            LOG("tid %d does not exist. ignoring explicit dump request\n",
-                    out_request->tid);
-            return -1;
-        }
-    } else {
-        /* No one else is allowed to dump arbitrary processes. */
-        return -1;
+    // 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) {
+      LOG("tid %d does not exist. ignoring explicit dump request\n", out_request->tid);
+      return -1;
     }
-    return 0;
+  } else {
+    // No one else is allowed to dump arbitrary processes.
+    return -1;
+  }
+  return 0;
 }
 
 static bool should_attach_gdb(debugger_request_t* request) {
-    if (request->action == DEBUGGER_ACTION_CRASH) {
-        char value[PROPERTY_VALUE_MAX];
-        property_get("debug.db.uid", value, "-1");
-        int debug_uid = atoi(value);
-        return debug_uid >= 0 && request->uid <= (uid_t)debug_uid;
-    }
-    return false;
+  if (request->action == DEBUGGER_ACTION_CRASH) {
+    char value[PROPERTY_VALUE_MAX];
+    property_get("debug.db.uid", value, "-1");
+    int debug_uid = atoi(value);
+    return debug_uid >= 0 && request->uid <= (uid_t)debug_uid;
+  }
+  return false;
 }
 
 static void handle_request(int fd) {
-    XLOG("handle_request(%d)\n", fd);
-
-    debugger_request_t request;
-    memset(&request, 0, sizeof(request));
-    int status = read_request(fd, &request);
-    if (!status) {
-        XLOG("BOOM: pid=%d uid=%d gid=%d tid=%d\n",
-            request.pid, request.uid, request.gid, request.tid);
-
-        /* 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 bionic/libc/linker/debugger.c, in function
-         * debugger_signal_handler().
-         */
-        if (ptrace(PTRACE_ATTACH, request.tid, 0, 0)) {
-            LOG("ptrace attach failed: %s\n", strerror(errno));
-        } else {
-            bool detach_failed = false;
-            bool attach_gdb = should_attach_gdb(&request);
-            if (TEMP_FAILURE_RETRY(write(fd, "\0", 1)) != 1) {
-                LOG("failed responding to client: %s\n", strerror(errno));
-            } else {
-                char* tombstone_path = NULL;
-
-                if (request.action == DEBUGGER_ACTION_CRASH) {
-                    close(fd);
-                    fd = -1;
-                }
+  XLOG("handle_request(%d)\n", fd);
+
+  debugger_request_t request;
+  memset(&request, 0, sizeof(request));
+  int status = read_request(fd, &request);
+  if (!status) {
+    XLOG("BOOM: pid=%d uid=%d gid=%d tid=%d\n",
+         request.pid, request.uid, request.gid, request.tid);
+
+    // 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 bionic/libc/linker/debugger.c, in function
+    // debugger_signal_handler().
+    if (ptrace(PTRACE_ATTACH, request.tid, 0, 0)) {
+      LOG("ptrace attach failed: %s\n", strerror(errno));
+    } else {
+      bool detach_failed = false;
+      bool attach_gdb = should_attach_gdb(&request);
+      if (TEMP_FAILURE_RETRY(write(fd, "\0", 1)) != 1) {
+        LOG("failed responding to client: %s\n", strerror(errno));
+      } else {
+        char* tombstone_path = NULL;
+
+        if (request.action == DEBUGGER_ACTION_CRASH) {
+          close(fd);
+          fd = -1;
+        }
 
-                int total_sleep_time_usec = 0;
-                for (;;) {
-                    int signal = wait_for_signal(request.tid, &total_sleep_time_usec);
-                    if (signal < 0) {
-                        break;
-                    }
-
-                    switch (signal) {
-                    case SIGSTOP:
-                        if (request.action == DEBUGGER_ACTION_DUMP_TOMBSTONE) {
-                            XLOG("stopped -- dumping to tombstone\n");
-                            tombstone_path = engrave_tombstone(request.pid, request.tid,
-                                    signal, request.abort_msg_address, true, true, &detach_failed,
-                                    &total_sleep_time_usec);
-                        } else if (request.action == DEBUGGER_ACTION_DUMP_BACKTRACE) {
-                            XLOG("stopped -- dumping to fd\n");
-                            dump_backtrace(fd, -1,
-                                    request.pid, request.tid, &detach_failed,
-                                    &total_sleep_time_usec);
-                        } else {
-                            XLOG("stopped -- continuing\n");
-                            status = ptrace(PTRACE_CONT, request.tid, 0, 0);
-                            if (status) {
-                                LOG("ptrace continue failed: %s\n", strerror(errno));
-                            }
-                            continue; /* loop again */
-                        }
-                        break;
-
-                    case SIGILL:
-                    case SIGABRT:
-                    case SIGBUS:
-                    case SIGFPE:
-                    case SIGSEGV:
-                    case SIGPIPE:
+        int total_sleep_time_usec = 0;
+        for (;;) {
+          int signal = wait_for_signal(request.tid, &total_sleep_time_usec);
+          if (signal < 0) {
+            break;
+          }
+
+          switch (signal) {
+            case SIGSTOP:
+              if (request.action == DEBUGGER_ACTION_DUMP_TOMBSTONE) {
+                XLOG("stopped -- dumping to tombstone\n");
+                tombstone_path = engrave_tombstone(
+                    request.pid, request.tid, signal, request.abort_msg_address, true, true,
+                    &detach_failed, &total_sleep_time_usec);
+              } else if (request.action == DEBUGGER_ACTION_DUMP_BACKTRACE) {
+                XLOG("stopped -- dumping to fd\n");
+                dump_backtrace(fd, -1, request.pid, request.tid, &detach_failed,
+                               &total_sleep_time_usec);
+              } else {
+                XLOG("stopped -- continuing\n");
+                status = ptrace(PTRACE_CONT, request.tid, 0, 0);
+                if (status) {
+                  LOG("ptrace continue failed: %s\n", strerror(errno));
+                }
+                continue; // loop again
+              }
+              break;
+
+            case SIGILL:
+            case SIGABRT:
+            case SIGBUS:
+            case SIGFPE:
+            case SIGSEGV:
+            case SIGPIPE:
 #ifdef SIGSTKFLT
-                    case SIGSTKFLT:
+            case SIGSTKFLT:
 #endif
-                        {
-                        XLOG("stopped -- fatal signal\n");
-                        /*
-                         * Send a SIGSTOP to the process to make all of
-                         * the non-signaled threads stop moving.  Without
-                         * this we get a lot of "ptrace detach failed:
-                         * No such process".
-                         */
-                        kill(request.pid, SIGSTOP);
-                        /* don't dump sibling threads when attaching to GDB because it
-                         * makes the process less reliable, apparently... */
-                        tombstone_path = engrave_tombstone(request.pid, request.tid,
-                                signal, request.abort_msg_address, !attach_gdb, false,
-                                &detach_failed, &total_sleep_time_usec);
-                        break;
-                    }
-
-                    default:
-                        XLOG("stopped -- unexpected signal\n");
-                        LOG("process stopped due to unexpected signal %d\n", signal);
-                        break;
-                    }
-                    break;
-                }
-
-                if (request.action == DEBUGGER_ACTION_DUMP_TOMBSTONE) {
-                    if (tombstone_path) {
-                        write(fd, tombstone_path, strlen(tombstone_path));
-                    }
-                    close(fd);
-                    fd = -1;
-                }
-                free(tombstone_path);
-            }
-
-            XLOG("detaching\n");
-            if (attach_gdb) {
-                /* stop the process so we can debug */
-                kill(request.pid, SIGSTOP);
-
-                /* detach so we can attach gdbserver */
-                if (ptrace(PTRACE_DETACH, request.tid, 0, 0)) {
-                    LOG("ptrace detach from %d failed: %s\n", request.tid, strerror(errno));
-                    detach_failed = true;
-                }
+              XLOG("stopped -- fatal signal\n");
+              // Send a SIGSTOP to the process to make all of
+              // the non-signaled threads stop moving.  Without
+              // this we get a lot of "ptrace detach failed:
+              // No such process".
+              kill(request.pid, SIGSTOP);
+              // don't dump sibling threads when attaching to GDB because it
+              // makes the process less reliable, apparently...
+              tombstone_path = engrave_tombstone(
+                  request.pid, request.tid, signal, request.abort_msg_address, !attach_gdb,
+                  false, &detach_failed, &total_sleep_time_usec);
+              break;
+
+            default:
+              XLOG("stopped -- unexpected signal\n");
+              LOG("process stopped due to unexpected signal %d\n", signal);
+              break;
+          }
+          break;
+        }
 
-                /*
-                 * if debug.db.uid is set, its value indicates if we should wait
-                 * for user action for the crashing process.
-                 * in this case, we log a message and turn the debug LED on
-                 * waiting for a gdb connection (for instance)
-                 */
-                wait_for_user_action(request.pid);
-            } else {
-                /* just detach */
-                if (ptrace(PTRACE_DETACH, request.tid, 0, 0)) {
-                    LOG("ptrace detach from %d failed: %s\n", request.tid, strerror(errno));
-                    detach_failed = true;
-                }
-            }
-
-            /* resume stopped process (so it can crash in peace). */
-            kill(request.pid, SIGCONT);
-
-            /* If we didn't successfully detach, we're still the parent, and the
-             * actual parent won't receive a death notification via wait(2).  At this point
-             * there's not much we can do about that. */
-            if (detach_failed) {
-                LOG("debuggerd committing suicide to free the zombie!\n");
-                kill(getpid(), SIGKILL);
-            }
+        if (request.action == DEBUGGER_ACTION_DUMP_TOMBSTONE) {
+          if (tombstone_path) {
+            write(fd, tombstone_path, strlen(tombstone_path));
+          }
+          close(fd);
+          fd = -1;
+        }
+        free(tombstone_path);
+      }
+
+      XLOG("detaching\n");
+      if (attach_gdb) {
+        // stop the process so we can debug
+        kill(request.pid, SIGSTOP);
+
+        // detach so we can attach gdbserver
+        if (ptrace(PTRACE_DETACH, request.tid, 0, 0)) {
+          LOG("ptrace detach from %d failed: %s\n", request.tid, strerror(errno));
+          detach_failed = true;
         }
 
+        // if debug.db.uid is set, its value indicates if we should wait
+        // for user action for the crashing process.
+        // in this case, we log a message and turn the debug LED on
+        // waiting for a gdb connection (for instance)
+        wait_for_user_action(request.pid);
+      } else {
+        // just detach
+        if (ptrace(PTRACE_DETACH, request.tid, 0, 0)) {
+          LOG("ptrace detach from %d failed: %s\n", request.tid, strerror(errno));
+          detach_failed = true;
+        }
+      }
+
+      // resume stopped process (so it can crash in peace).
+      kill(request.pid, SIGCONT);
+
+      // If we didn't successfully detach, we're still the parent, and the
+      // actual parent won't receive a death notification via wait(2).  At this point
+      // there's not much we can do about that.
+      if (detach_failed) {
+        LOG("debuggerd committing suicide to free the zombie!\n");
+        kill(getpid(), SIGKILL);
+      }
     }
-    if (fd >= 0) {
-        close(fd);
-    }
+
+  }
+  if (fd >= 0) {
+    close(fd);
+  }
 }
 
 static int do_server() {
-    int s;
-    struct sigaction act;
-    int logsocket = -1;
-
-    /*
-     * debuggerd crashes can't be reported to debuggerd.  Reset all of the
-     * crash handlers.
-     */
-    signal(SIGILL, SIG_DFL);
-    signal(SIGABRT, SIG_DFL);
-    signal(SIGBUS, SIG_DFL);
-    signal(SIGFPE, SIG_DFL);
-    signal(SIGSEGV, SIG_DFL);
+  int s;
+  struct sigaction act;
+  int logsocket = -1;
+
+  // debuggerd crashes can't be reported to debuggerd.  Reset all of the
+  // crash handlers.
+  signal(SIGILL, SIG_DFL);
+  signal(SIGABRT, SIG_DFL);
+  signal(SIGBUS, SIG_DFL);
+  signal(SIGFPE, SIG_DFL);
+  signal(SIGSEGV, SIG_DFL);
 #ifdef SIGSTKFLT
-    signal(SIGSTKFLT, SIG_DFL);
+  signal(SIGSTKFLT, SIG_DFL);
 #endif
 
-    // Ignore failed writes to closed sockets
-    signal(SIGPIPE, SIG_IGN);
+  // Ignore failed writes to closed sockets
+  signal(SIGPIPE, SIG_IGN);
 
-    logsocket = socket_local_client("logd",
-            ANDROID_SOCKET_NAMESPACE_ABSTRACT, SOCK_DGRAM);
-    if(logsocket < 0) {
-        logsocket = -1;
-    } else {
-        fcntl(logsocket, F_SETFD, FD_CLOEXEC);
-    }
+  logsocket = socket_local_client("logd", ANDROID_SOCKET_NAMESPACE_ABSTRACT, SOCK_DGRAM);
+  if (logsocket < 0) {
+    logsocket = -1;
+  } else {
+    fcntl(logsocket, F_SETFD, FD_CLOEXEC);
+  }
 
-    act.sa_handler = SIG_DFL;
-    sigemptyset(&act.sa_mask);
-    sigaddset(&act.sa_mask,SIGCHLD);
-    act.sa_flags = SA_NOCLDWAIT;
-    sigaction(SIGCHLD, &act, 0);
-
-    s = socket_local_server(DEBUGGER_SOCKET_NAME,
-            ANDROID_SOCKET_NAMESPACE_ABSTRACT, SOCK_STREAM);
-    if(s < 0) return 1;
-    fcntl(s, F_SETFD, FD_CLOEXEC);
-
-    LOG("debuggerd: " __DATE__ " " __TIME__ "\n");
-
-    for(;;) {
-        struct sockaddr addr;
-        socklen_t alen;
-        int fd;
-
-        alen = sizeof(addr);
-        XLOG("waiting for connection\n");
-        fd = accept(s, &addr, &alen);
-        if(fd < 0) {
-            XLOG("accept failed: %s\n", strerror(errno));
-            continue;
-        }
+  act.sa_handler = SIG_DFL;
+  sigemptyset(&act.sa_mask);
+  sigaddset(&act.sa_mask,SIGCHLD);
+  act.sa_flags = SA_NOCLDWAIT;
+  sigaction(SIGCHLD, &act, 0);
 
-        fcntl(fd, F_SETFD, FD_CLOEXEC);
+  s = socket_local_server(DEBUGGER_SOCKET_NAME, ANDROID_SOCKET_NAMESPACE_ABSTRACT, SOCK_STREAM);
+  if (s < 0)
+    return 1;
+  fcntl(s, F_SETFD, FD_CLOEXEC);
 
-        handle_request(fd);
+  LOG("debuggerd: " __DATE__ " " __TIME__ "\n");
+
+  for (;;) {
+    struct sockaddr addr;
+    socklen_t alen;
+    int fd;
+
+    alen = sizeof(addr);
+    XLOG("waiting for connection\n");
+    fd = accept(s, &addr, &alen);
+    if (fd < 0) {
+      XLOG("accept failed: %s\n", strerror(errno));
+      continue;
     }
-    return 0;
+
+    fcntl(fd, F_SETFD, FD_CLOEXEC);
+
+    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);
+  fprintf(stdout, "Sending request to dump task %d.\n", tid);
 
-    if (dump_backtrace) {
-        fflush(stdout);
-        if (dump_backtrace_to_file(tid, fileno(stdout)) < 0) {
-            fputs("Error dumping backtrace.\n", stderr);
-            return 1;
-        }
-    } else {
-        char tombstone_path[PATH_MAX];
-        if (dump_tombstone(tid, tombstone_path, sizeof(tombstone_path)) < 0) {
-            fputs("Error dumping tombstone.\n", stderr);
-            return 1;
-        }
-        fprintf(stderr, "Tombstone written to: %s\n", tombstone_path);
+  if (dump_backtrace) {
+    fflush(stdout);
+    if (dump_backtrace_to_file(tid, fileno(stdout)) < 0) {
+      fputs("Error dumping backtrace.\n", stderr);
+      return 1;
     }
-    return 0;
+  } else {
+    char tombstone_path[PATH_MAX];
+    if (dump_tombstone(tid, tombstone_path, sizeof(tombstone_path)) < 0) {
+      fputs("Error dumping tombstone.\n", stderr);
+      return 1;
+    }
+    fprintf(stderr, "Tombstone written to: %s\n", tombstone_path);
+  }
+  return 0;
 }
 
 static void usage() {
-    fputs("Usage: -b [<tid>]\n"
-            "  -b dump backtrace to console, otherwise dump full tombstone file\n"
-            "\n"
-            "If tid specified, sends a request to debuggerd to dump that task.\n"
-            "Otherwise, starts the debuggerd server.\n", stderr);
+  fputs("Usage: -b [<tid>]\n"
+        "  -b dump backtrace to console, otherwise dump full tombstone file\n"
+        "\n"
+        "If tid specified, sends a request to debuggerd to dump that task.\n"
+        "Otherwise, starts the debuggerd server.\n", stderr);
 }
 
 int main(int argc, char** argv) {
-    if (argc == 1) {
-        return do_server();
-    }
-
-    bool dump_backtrace = false;
-    bool have_tid = false;
-    pid_t tid = 0;
-    for (int i = 1; i < argc; i++) {
-        if (!strcmp(argv[i], "-b")) {
-            dump_backtrace = true;
-        } else if (!have_tid) {
-            tid = atoi(argv[i]);
-            have_tid = true;
-        } else {
-            usage();
-            return 1;
-        }
-    }
-    if (!have_tid) {
-        usage();
-        return 1;
+  if (argc == 1) {
+    return do_server();
+  }
+
+  bool dump_backtrace = false;
+  bool have_tid = false;
+  pid_t tid = 0;
+  for (int i = 1; i < argc; i++) {
+    if (!strcmp(argv[i], "-b")) {
+      dump_backtrace = true;
+    } else if (!have_tid) {
+      tid = atoi(argv[i]);
+      have_tid = true;
+    } else {
+      usage();
+      return 1;
     }
-    return do_explicit_dump(tid, dump_backtrace);
+  }
+  if (!have_tid) {
+    usage();
+    return 1;
+  }
+  return do_explicit_dump(tid, dump_backtrace);
 }