auto import from //depot/cupcake/@135843

1 files changed, 852 insertions, 0 deletions

diff --git a/debuggerd/debuggerd.c b/debuggerd/debuggerd.c
new file mode 100644
index 0000000..9394e1c
--- /dev/null
+++ b/debuggerd/debuggerd.c
@@ -0,0 +1,852 @@
+/* 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.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <pthread.h>
+#include <stdarg.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <dirent.h>
+
+#include <sys/ptrace.h>
+#include <sys/wait.h>
+#include <sys/exec_elf.h>
+#include <sys/stat.h>
+
+#include <cutils/sockets.h>
+#include <cutils/logd.h>
+#include <cutils/sockets.h>
+#include <cutils/properties.h>
+
+#include <linux/input.h>
+
+#include <private/android_filesystem_config.h>
+
+#include "utility.h"
+
+/* Main entry point to get the backtrace from the crashing process */
+extern int unwind_backtrace_with_ptrace(int tfd, pid_t pid, mapinfo *map,
+                                        unsigned int sp_list[],
+                                        int *frame0_pc_sane,
+                                        bool at_fault);
+
+static char **process_name_ptr;
+
+static int logsocket = -1;
+
+#define ANDROID_LOG_INFO 4
+
+/* Log information onto the tombstone */
+void _LOG(int tfd, bool in_tombstone_only, const char *fmt, ...)
+{
+    char buf[128];
+    
+    va_list ap;
+    va_start(ap, fmt);
+
+    if (tfd >= 0) {
+        int len;
+        vsnprintf(buf, sizeof(buf), fmt, ap);
+        len = strlen(buf);
+        if(tfd >= 0) write(tfd, buf, len);
+    }
+
+    if (!in_tombstone_only)
+        __android_log_vprint(ANDROID_LOG_INFO, "DEBUG", fmt, ap);
+}
+
+#define LOG(fmt...) _LOG(-1, 0, fmt)
+#if 0
+#define XLOG(fmt...) _LOG(-1, 0, fmt)
+#else
+#define XLOG(fmt...) do {} while(0)
+#endif
+
+// 6f000000-6f01e000 rwxp 00000000 00:0c 16389419   /system/lib/libcomposer.so
+// 012345678901234567890123456789012345678901234567890123456789
+// 0         1         2         3         4         5
+
+mapinfo *parse_maps_line(char *line)
+{
+    mapinfo *mi;
+    int len = strlen(line);
+
+    if(len < 1) return 0;
+    line[--len] = 0;
+    
+    if(len < 50) return 0;
+    if(line[20] != 'x') return 0;
+
+    mi = malloc(sizeof(mapinfo) + (len - 47));
+    if(mi == 0) return 0;
+    
+    mi->start = strtoul(line, 0, 16);
+    mi->end = strtoul(line + 9, 0, 16);
+    /* To be filled in parse_exidx_info if the mapped section starts with 
+     * elf_header
+     */
+    mi->exidx_start = mi->exidx_end = 0;
+    mi->next = 0;
+    strcpy(mi->name, line + 49);
+
+    return mi;
+}
+
+void dump_build_info(int tfd)
+{
+    char fingerprint[PROPERTY_VALUE_MAX];
+
+    property_get("ro.build.fingerprint", fingerprint, "unknown");
+
+    _LOG(tfd, false, "Build fingerprint: '%s'\n", fingerprint);
+}
+
+
+void dump_stack_and_code(int tfd, int pid, mapinfo *map, 
+                         int unwind_depth, unsigned int sp_list[],
+                         int frame0_pc_sane, bool at_fault)
+{
+    unsigned int sp, pc, p, end, data;
+    struct pt_regs r;
+    int sp_depth;
+    bool only_in_tombstone = !at_fault;
+
+    if(ptrace(PTRACE_GETREGS, pid, 0, &r)) return;
+    sp = r.ARM_sp;
+    pc = r.ARM_pc;
+
+    /* Died because calling the weeds - dump
+     * the code around the PC in the next frame instead.
+     */
+    if (frame0_pc_sane == 0) {
+        pc = r.ARM_lr;
+    }
+
+    _LOG(tfd, true, "code%s:\n", frame0_pc_sane ? "" : " (around frame #01)");
+
+    end = p = pc & ~3;
+    p -= 16;
+
+    /* Dump the code as:
+     *  PC         contents
+     *  00008d34   fffffcd0 4c0eb530 b0934a0e 1c05447c
+     *  00008d44   f7ff18a0 490ced94 68035860 d0012b00
+     */
+    while (p <= end) {
+        int i;
+
+        _LOG(tfd, true, " %08x  ", p);
+        for (i = 0; i < 4; i++) {
+            data = ptrace(PTRACE_PEEKTEXT, pid, (void*)p, NULL);
+            _LOG(tfd, true, " %08x", data);
+            p += 4;
+        }
+        _LOG(tfd, true, "\n", p);
+    }
+
+    p = sp - 64;
+    p &= ~3;
+    if (unwind_depth != 0) {
+        if (unwind_depth < STACK_CONTENT_DEPTH) {
+            end = sp_list[unwind_depth-1];
+        }
+        else {
+            end = sp_list[STACK_CONTENT_DEPTH-1];
+        }
+    }
+    else {
+        end = sp | 0x000000ff;
+        end += 0xff;
+    }
+
+    _LOG(tfd, only_in_tombstone, "stack:\n");
+
+    /* If the crash is due to PC == 0, there will be two frames that
+     * have identical SP value.
+     */
+    if (sp_list[0] == sp_list[1]) {
+        sp_depth = 1;
+    }
+    else {
+        sp_depth = 0;
+    }
+
+    while (p <= end) {
+         char *prompt; 
+         char level[16];
+         data = ptrace(PTRACE_PEEKTEXT, pid, (void*)p, NULL);
+         if (p == sp_list[sp_depth]) {
+             sprintf(level, "#%02d", sp_depth++);
+             prompt = level;
+         }
+         else {
+             prompt = "   ";
+         }
+         
+         /* Print the stack content in the log for the first 3 frames. For the
+          * rest only print them in the tombstone file.
+          */
+         _LOG(tfd, (sp_depth > 2) || only_in_tombstone, 
+              "%s %08x  %08x  %s\n", prompt, p, data, 
+              map_to_name(map, data, ""));
+         p += 4;
+    }
+    /* print another 64-byte of stack data after the last frame */
+
+    end = p+64;
+    while (p <= end) {
+         data = ptrace(PTRACE_PEEKTEXT, pid, (void*)p, NULL);
+         _LOG(tfd, (sp_depth > 2) || only_in_tombstone, 
+              "    %08x  %08x  %s\n", p, data, 
+              map_to_name(map, data, ""));
+         p += 4;
+    }
+}
+
+void dump_pc_and_lr(int tfd, int pid, mapinfo *map, int unwound_level, 
+                    bool at_fault)
+{
+    struct pt_regs r;
+
+    if(ptrace(PTRACE_GETREGS, pid, 0, &r)) {
+        _LOG(tfd, !at_fault, "tid %d not responding!\n", pid);
+        return;
+    }
+
+    if (unwound_level == 0) {
+        _LOG(tfd, !at_fault, "         #%02d  pc %08x  %s\n", 0, r.ARM_pc,
+             map_to_name(map, r.ARM_pc, "<unknown>"));
+    }
+    _LOG(tfd, !at_fault, "         #%02d  lr %08x  %s\n", 1, r.ARM_lr,
+            map_to_name(map, r.ARM_lr, "<unknown>"));
+}
+
+void dump_registers(int tfd, int pid, bool at_fault) 
+{
+    struct pt_regs r;
+    bool only_in_tombstone = !at_fault;
+
+    if(ptrace(PTRACE_GETREGS, pid, 0, &r)) {
+        _LOG(tfd, only_in_tombstone, 
+             "cannot get registers: %s\n", strerror(errno));
+        return;
+    }
+    
+    _LOG(tfd, only_in_tombstone, " r0 %08x  r1 %08x  r2 %08x  r3 %08x\n",
+         r.ARM_r0, r.ARM_r1, r.ARM_r2, r.ARM_r3);
+    _LOG(tfd, only_in_tombstone, " r4 %08x  r5 %08x  r6 %08x  r7 %08x\n",
+         r.ARM_r4, r.ARM_r5, r.ARM_r6, r.ARM_r7);
+    _LOG(tfd, only_in_tombstone, " r8 %08x  r9 %08x  10 %08x  fp %08x\n",
+         r.ARM_r8, r.ARM_r9, r.ARM_r10, r.ARM_fp);
+    _LOG(tfd, only_in_tombstone, 
+         " ip %08x  sp %08x  lr %08x  pc %08x  cpsr %08x\n",
+         r.ARM_ip, r.ARM_sp, r.ARM_lr, r.ARM_pc, r.ARM_cpsr);  
+}
+
+const char *get_signame(int sig)
+{
+    switch(sig) {
+    case SIGILL:     return "SIGILL";
+    case SIGABRT:    return "SIGABRT";
+    case SIGBUS:     return "SIGBUS";
+    case SIGFPE:     return "SIGFPE";
+    case SIGSEGV:    return "SIGSEGV";
+    case SIGSTKFLT:  return "SIGSTKFLT";
+    default:         return "?";
+    }
+}
+
+void dump_fault_addr(int tfd, int pid, int sig)
+{
+    siginfo_t si;
+    
+    memset(&si, 0, sizeof(si));
+    if(ptrace(PTRACE_GETSIGINFO, pid, 0, &si)){
+        _LOG(tfd, false, "cannot get siginfo: %s\n", strerror(errno));
+    } else {
+        _LOG(tfd, false, "signal %d (%s), fault addr %08x\n",
+            sig, get_signame(sig), si.si_addr);
+    }
+}
+
+void dump_crash_banner(int tfd, unsigned pid, unsigned tid, int sig)
+{
+    char data[1024];
+    char *x = 0;
+    FILE *fp;
+    
+    sprintf(data, "/proc/%d/cmdline", pid);
+    fp = fopen(data, "r");
+    if(fp) {
+        x = fgets(data, 1024, fp);
+        fclose(fp);
+    }
+    
+    _LOG(tfd, false,
+         "*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***\n");
+    dump_build_info(tfd);
+    _LOG(tfd, false, "pid: %d, tid: %d  >>> %s <<<\n",
+         pid, tid, x ? x : "UNKNOWN");
+    
+    if(sig) dump_fault_addr(tfd, tid, sig);
+}
+
+static void parse_exidx_info(mapinfo *milist, pid_t pid)
+{
+    mapinfo *mi;
+    for (mi = milist; mi != NULL; mi = mi->next) {
+        Elf32_Ehdr ehdr;
+
+        memset(&ehdr, 0, sizeof(Elf32_Ehdr));
+        /* Read in sizeof(Elf32_Ehdr) worth of data from the beginning of 
+         * mapped section.
+         */
+        get_remote_struct(pid, (void *) (mi->start), &ehdr, 
+                          sizeof(Elf32_Ehdr));
+        /* Check if it has the matching magic words */
+        if (IS_ELF(ehdr)) {
+            Elf32_Phdr phdr;
+            Elf32_Phdr *ptr;
+            int i;
+
+            ptr = (Elf32_Phdr *) (mi->start + ehdr.e_phoff);
+            for (i = 0; i < ehdr.e_phnum; i++) {
+                /* Parse the program header */
+                get_remote_struct(pid, (void *) ptr+i, &phdr, 
+                                  sizeof(Elf32_Phdr));
+                /* Found a EXIDX segment? */
+                if (phdr.p_type == PT_ARM_EXIDX) {
+                    mi->exidx_start = mi->start + phdr.p_offset;
+                    mi->exidx_end = mi->exidx_start + phdr.p_filesz;
+                    break;
+                }
+            }
+        }
+    }
+}
+
+void dump_crash_report(int tfd, unsigned pid, unsigned tid, bool at_fault)
+{
+    char data[1024];
+    FILE *fp;
+    mapinfo *milist = 0;
+    unsigned int sp_list[STACK_CONTENT_DEPTH];
+    int stack_depth;
+    int frame0_pc_sane = 1;
+    
+    if (!at_fault) {
+        _LOG(tfd, true,
+         "--- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---\n");
+        _LOG(tfd, true, "pid: %d, tid: %d\n", pid, tid);
+    }
+
+    dump_registers(tfd, tid, at_fault);
+    
+    /* Clear stack pointer records */
+    memset(sp_list, 0, sizeof(sp_list));
+
+    sprintf(data, "/proc/%d/maps", pid);
+    fp = fopen(data, "r");
+    if(fp) {
+        while(fgets(data, 1024, fp)) {
+            mapinfo *mi = parse_maps_line(data);
+            if(mi) {
+                mi->next = milist;
+                milist = mi;
+            }
+        }
+        fclose(fp);
+    }
+
+    parse_exidx_info(milist, tid);
+
+    /* If stack unwinder fails, use the default solution to dump the stack
+     * content.
+     */
+    stack_depth = unwind_backtrace_with_ptrace(tfd, tid, milist, sp_list,
+                                               &frame0_pc_sane, at_fault);
+
+    /* The stack unwinder should at least unwind two levels of stack. If less
+     * level is seen we make sure at lease pc and lr are dumped.
+     */
+    if (stack_depth < 2) {
+        dump_pc_and_lr(tfd, tid, milist, stack_depth, at_fault);
+    }
+
+    dump_stack_and_code(tfd, tid, milist, stack_depth, sp_list, frame0_pc_sane,
+                        at_fault);
+
+    while(milist) {
+        mapinfo *next = milist->next;
+        free(milist);
+        milist = next;
+    }
+}
+
+/* FIXME: unused: use it or lose it*/
+#if 0
+static
+void start_gdbserver_vs(int pid, int port)
+{
+    pid_t p;
+    char *args[5];
+    char commspec[16];
+    char pidspec[16];
+    
+    p = fork();
+    if(p < 0) {
+        LOG("could not fork()\n");
+        return;
+    }
+
+    if(p == 0) {
+        sprintf(commspec, ":%d", port);
+        sprintf(pidspec, "%d", pid);
+        args[0] = "/system/bin/gdbserver";
+        args[1] = commspec;
+        args[2] = "--attach";
+        args[3] = pidspec;
+        args[4] = 0;
+        exit(execv(args[0], args));
+    } else {
+        LOG("gdbserver pid=%d port=%d targetpid=%d\n",
+            p, port, pid);
+
+        sleep(5);
+    }
+}
+#endif
+
+#define MAX_TOMBSTONES	10
+
+#define typecheck(x,y) {    \
+    typeof(x) __dummy1;     \
+    typeof(y) __dummy2;     \
+    (void)(&__dummy1 == &__dummy2); }
+
+#define TOMBSTONE_DIR	"/data/tombstones"
+
+/*
+ * find_and_open_tombstone - find an available tombstone slot, if any, of the
+ * form tombstone_XX where XX is 00 to MAX_TOMBSTONES-1, inclusive. If no
+ * file is available, we reuse the least-recently-modified file.
+ */
+static int find_and_open_tombstone(void)
+{
+    unsigned long mtime = ULONG_MAX;
+    struct stat sb;
+    char path[128];
+    int fd, i, oldest = 0;
+
+    /*
+     * XXX: Our stat.st_mtime isn't time_t. If it changes, as it probably ought
+     * to, our logic breaks. This check will generate a warning if that happens.
+     */
+    typecheck(mtime, sb.st_mtime);
+
+    /*
+     * In a single wolf-like pass, find an available slot and, in case none
+     * exist, find and record the least-recently-modified file.
+     */
+    for (i = 0; i < MAX_TOMBSTONES; i++) {
+        snprintf(path, sizeof(path), TOMBSTONE_DIR"/tombstone_%02d", i);
+
+        if (!stat(path, &sb)) {
+            if (sb.st_mtime < mtime) {
+                oldest = i;
+                mtime = sb.st_mtime;
+            }
+            continue;
+        }
+        if (errno != ENOENT)
+            continue;
+
+        fd = open(path, O_CREAT | O_EXCL | O_WRONLY, 0600);
+        if (fd < 0)
+            continue;	/* raced ? */
+
+        fchown(fd, AID_SYSTEM, AID_SYSTEM);
+        return fd;
+    }
+
+    /* we didn't find an available file, so we clobber the oldest one */
+    snprintf(path, sizeof(path), TOMBSTONE_DIR"/tombstone_%02d", oldest);
+    fd = open(path, O_CREAT | O_TRUNC | O_WRONLY, 0600);
+    fchown(fd, AID_SYSTEM, AID_SYSTEM);
+
+    return fd;
+}
+
+/* Return true if some thread is not detached cleanly */
+static bool dump_sibling_thread_report(int tfd, unsigned pid, unsigned tid)
+{
+    char task_path[1024];
+
+    sprintf(task_path, "/proc/%d/task", pid);
+    DIR *d;
+    struct dirent *de;
+    int need_cleanup = 0;
+
+    d = opendir(task_path);
+    /* Bail early if cannot open the task directory */
+    if (d == NULL) {
+        XLOG("Cannot open /proc/%d/task\n", pid);
+        return false;
+    }
+    while ((de = readdir(d)) != NULL) {
+        unsigned new_tid;
+        /* Ignore "." and ".." */
+        if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, "..")) 
+            continue;
+        new_tid = atoi(de->d_name);
+        /* The main thread at fault has been handled individually */
+        if (new_tid == tid)
+            continue;
+
+        /* Skip this thread if cannot ptrace it */
+        if (ptrace(PTRACE_ATTACH, new_tid, 0, 0) < 0)
+            continue;
+
+        dump_crash_report(tfd, pid, new_tid, false);
+        need_cleanup |= ptrace(PTRACE_DETACH, new_tid, 0, 0);
+    }
+    closedir(d);
+    return need_cleanup != 0;
+}
+
+/* Return true if some thread is not detached cleanly */
+static bool engrave_tombstone(unsigned pid, unsigned tid, int debug_uid, 
+                              int signal)
+{
+    int fd;
+    bool need_cleanup = false;
+
+    mkdir(TOMBSTONE_DIR, 0755);
+    chown(TOMBSTONE_DIR, AID_SYSTEM, AID_SYSTEM);
+
+    fd = find_and_open_tombstone();
+    if (fd < 0)
+        return need_cleanup;
+
+    dump_crash_banner(fd, pid, tid, signal);
+    dump_crash_report(fd, pid, tid, true);
+    /* 
+     * If the user has requested to attach gdb, don't collect the per-thread
+     * information as it increases the chance to lose track of the process.
+     */
+    if ((signed)pid > debug_uid) {
+        need_cleanup = dump_sibling_thread_report(fd, pid, tid);
+    }
+
+    close(fd);
+    return need_cleanup;
+}
+
+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 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 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");
+}
+
+extern int init_getevent();
+extern void uninit_getevent();
+extern int get_event(struct input_event* event, int timeout);
+
+static void wait_for_user_action(unsigned tid, struct ucred* cr)
+{
+    (void)tid;
+    /* First log a helpful message */
+    LOG(    "********************************************************\n"
+            "* process %d crashed. debuggerd waiting for gdbserver   \n"
+            "*                                                       \n"
+            "*     adb shell gdbserver :port --attach %d &           \n"
+            "*                                                       \n"
+            "* and press the HOME key.                               \n"
+            "********************************************************\n",                
+            cr->pid, cr->pid);
+
+    /* wait for HOME key */
+    if (init_getevent() == 0) {
+        int ms = 1200 / 10;
+        int dit = 1;
+        int dah = 3*dit;
+        int _       = -dit;
+        int ___     = 3*_;
+        int _______ = 7*_;
+        const signed char codes[] = {
+           dit,_,dit,_,dit,___,dah,_,dah,_,dah,___,dit,_,dit,_,dit,_______
+        };
+        size_t s = 0;
+        struct input_event e;
+        int home = 0;
+        init_debug_led();
+        enable_debug_led();
+        do {
+            int timeout = abs((int)(codes[s])) * ms;
+            int res = get_event(&e, timeout);
+            if (res == 0) {
+                if (e.type==EV_KEY && e.code==KEY_HOME && e.value==0)
+                    home = 1;
+            } else if (res == 1) {
+                if (++s >= sizeof(codes)/sizeof(*codes))
+                    s = 0;
+                if (codes[s] > 0) {
+                    enable_debug_led();
+                } else {
+                    disable_debug_led();
+                }
+            }
+        } while (!home); 
+        uninit_getevent();
+    }
+
+    /* don't forget to turn debug led off */
+    disable_debug_led();
+    
+    /* close filedescriptor */
+    LOG("debuggerd resuming process %d", cr->pid);
+ }
+
+static void handle_crashing_process(int fd)
+{
+    char buf[64];
+    struct stat s;
+    unsigned tid;
+    struct ucred cr;
+    int n, len, status; 
+    int tid_attach_status = -1;
+    unsigned retry = 30;
+    bool need_cleanup = false;
+
+    char value[PROPERTY_VALUE_MAX];
+    property_get("debug.db.uid", value, "-1");
+    int debug_uid = atoi(value);
+    
+    XLOG("handle_crashing_process(%d)\n", fd);
+    
+    len = sizeof(cr);
+    n = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cr, &len);
+    if(n != 0) {
+        LOG("cannot get credentials\n");
+        goto done;
+    }
+
+    XLOG("reading tid\n");    
+    fcntl(fd, F_SETFL, O_NONBLOCK);
+    while((n = read(fd, &tid, sizeof(unsigned))) != sizeof(unsigned)) {
+        if(errno == EINTR) continue;
+        if(errno == EWOULDBLOCK) {
+            if(retry-- > 0) {
+                usleep(100 * 1000);
+                continue;
+            }
+            LOG("timed out reading tid\n");
+            goto done;
+        }
+        LOG("read failure? %s\n", strerror(errno));
+        goto done;
+    }
+
+    sprintf(buf,"/proc/%d/task/%d", cr.pid, tid);
+    if(stat(buf, &s)) {
+        LOG("tid %d does not exist in pid %d. ignorning debug request\n",
+            tid, cr.pid);
+        close(fd);
+        return;
+    }
+    
+    XLOG("BOOM: pid=%d uid=%d gid=%d tid=%d\n", cr.pid, cr.uid, cr.gid, tid);
+
+    tid_attach_status = ptrace(PTRACE_ATTACH, tid, 0, 0);
+    if(tid_attach_status < 0) {
+        LOG("ptrace attach failed: %s\n", strerror(errno));
+        goto done;
+    }
+
+    close(fd);
+    fd = -1;
+
+    for(;;) {
+        n = waitpid(tid, &status, __WALL);
+        
+        if(n < 0) {
+            if(errno == EAGAIN) continue;
+            LOG("waitpid failed: %s\n", strerror(errno));
+            goto done;
+        }
+
+        XLOG("waitpid: n=%d status=%08x\n", n, status);
+
+        if(WIFSTOPPED(status)){
+            n = WSTOPSIG(status);
+            switch(n) {
+            case SIGSTOP:
+                XLOG("stopped -- continuing\n");
+                n = ptrace(PTRACE_CONT, tid, 0, 0);
+                if(n) {
+                    LOG("ptrace failed: %s\n", strerror(errno));
+                    goto done;
+                }
+                continue;
+                
+            case SIGILL:
+            case SIGABRT:
+            case SIGBUS:
+            case SIGFPE:
+            case SIGSEGV:
+            case SIGSTKFLT: {
+                XLOG("stopped -- fatal signal\n");
+                need_cleanup = engrave_tombstone(cr.pid, tid, debug_uid, n);
+                kill(tid, SIGSTOP);
+                goto done;
+            }
+
+            default:
+                XLOG("stopped -- unexpected signal\n");
+                goto done;
+            }
+        } else {
+            XLOG("unexpected waitpid response\n");
+            goto done;
+        }
+    }
+    
+done:
+    XLOG("detaching\n");
+    
+    /* stop the process so we can debug */
+    kill(cr.pid, SIGSTOP);
+
+    /* 
+     * If a thread has been attached by ptrace, make sure it is detached 
+     * successfully otherwise we will get a zombie.
+     */ 
+    if (tid_attach_status == 0) {
+        int detach_status;
+        /* detach so we can attach gdbserver */
+        detach_status = ptrace(PTRACE_DETACH, tid, 0, 0);
+        need_cleanup |= (detach_status != 0);
+    }
+
+    /*
+     * 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)
+     */
+
+    if ((signed)cr.uid <= debug_uid) {
+        wait_for_user_action(tid, &cr);
+    }
+
+    /* resume stopped process (so it can crash in peace) */
+    kill(cr.pid, SIGCONT);
+
+    if (need_cleanup) {
+        LOG("debuggerd committing suicide to free the zombie!\n");
+        kill(getpid(), SIGKILL);
+    }
+
+    if(fd != -1) close(fd);
+}
+
+int main(int argc, char **argv)
+{
+    int s;
+    struct sigaction act;
+    
+    process_name_ptr = argv;
+    
+    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("android:debuggerd", 
+            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);
+        fd = accept(s, &addr, &alen);
+        if(fd < 0) continue;
+        
+        fcntl(fd, F_SETFD, FD_CLOEXEC);
+
+        handle_crashing_process(fd);
+    }
+    return 0;
+}