ACPR/android_system_core
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
android_system_core/debuggerd/debuggerd.c
Andy McFadden e5cc5396e8 Add log summary to tombstones 
When the tombstones are uploaded to APR, they're truncated at 64KB.
This causes the log data, which is at the end, to be lost if the
process has more than about 12 threads (which many do).

This change adds the last few lines of the log right below the
report for the crashing thread, where we should be guaranteed to
keep it.

Also, clean up trailing newlines on log messages (which end up in
the tombstone), and don't print a "------- log" banner if there
aren't any messages in that log file (e.g. slog).

Also also, don't try to show_nearby_maps unless this is the crashing
thread.

Bug 5471955

Change-Id: Iaa4fd2fafbaeda2f20bb95f202177d7744a91f9d
2011-10-18 20:20:14 -07:00

957 lines
27 KiB
C
Raw Blame History

/* 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 <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/logger.h>
#include <cutils/properties.h>
#include <linux/input.h>
#include <private/android_filesystem_config.h>
#include "debuggerd.h"
#include "utility.h"
#define ANDROID_LOG_INFO 4
void _LOG(int tfd, bool in_tombstone_only, const char *fmt, ...)
__attribute__ ((format(printf, 3, 4)));
/* Log information onto the tombstone */
void _LOG(int tfd, bool in_tombstone_only, const char *fmt, ...)
{
char buf[512];
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);
va_end(ap);
}
// 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; /* not expected */
line[--len] = 0;
if (len < 50) {
mi = malloc(sizeof(mapinfo) + 1);
} else {
mi = malloc(sizeof(mapinfo) + (len - 47));
}
if (mi == 0) return 0;
mi->isExecutable = (line[20] == 'x');
mi->start = strtoul(line, 0, 16);
mi->end = strtoul(line + 9, 0, 16);
/* To be filled in parse_elf_info if the mapped section starts with
* elf_header
*/
mi->exidx_start = mi->exidx_end = 0;
mi->symbols = 0;
mi->next = 0;
if (len < 50) {
mi->name[0] = '\0';
} else {
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);
}
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 "?";
}
}
const char *get_sigcode(int signo, int code)
{
switch (signo) {
case SIGILL:
switch (code) {
case ILL_ILLOPC: return "ILL_ILLOPC";
case ILL_ILLOPN: return "ILL_ILLOPN";
case ILL_ILLADR: return "ILL_ILLADR";
case ILL_ILLTRP: return "ILL_ILLTRP";
case ILL_PRVOPC: return "ILL_PRVOPC";
case ILL_PRVREG: return "ILL_PRVREG";
case ILL_COPROC: return "ILL_COPROC";
case ILL_BADSTK: return "ILL_BADSTK";
}
break;
case SIGBUS:
switch (code) {
case BUS_ADRALN: return "BUS_ADRALN";
case BUS_ADRERR: return "BUS_ADRERR";
case BUS_OBJERR: return "BUS_OBJERR";
}
break;
case SIGFPE:
switch (code) {
case FPE_INTDIV: return "FPE_INTDIV";
case FPE_INTOVF: return "FPE_INTOVF";
case FPE_FLTDIV: return "FPE_FLTDIV";
case FPE_FLTOVF: return "FPE_FLTOVF";
case FPE_FLTUND: return "FPE_FLTUND";
case FPE_FLTRES: return "FPE_FLTRES";
case FPE_FLTINV: return "FPE_FLTINV";
case FPE_FLTSUB: return "FPE_FLTSUB";
}
break;
case SIGSEGV:
switch (code) {
case SEGV_MAPERR: return "SEGV_MAPERR";
case SEGV_ACCERR: return "SEGV_ACCERR";
}
break;
}
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 if (signal_has_address(sig)) {
_LOG(tfd, false, "signal %d (%s), code %d (%s), fault addr %08x\n",
sig, get_signame(sig),
si.si_code, get_sigcode(sig, si.si_code),
(uintptr_t) si.si_addr);
} else {
_LOG(tfd, false, "signal %d (%s), code %d (%s), fault addr --------\n",
sig, get_signame(sig), si.si_code, get_sigcode(sig, si.si_code));
}
}
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_elf_info(mapinfo *milist, pid_t pid)
{
mapinfo *mi;
for (mi = milist; mi != NULL; mi = mi->next) {
if (!mi->isExecutable)
continue;
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, (char *) (ptr+i), &phdr,
sizeof(Elf32_Phdr));
#ifdef __arm__
/* 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;
}
#endif
}
/* Try to load symbols from this file */
mi->symbols = symbol_table_create(mi->name);
}
}
}
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;
#ifdef __arm__
int frame0_pc_sane = 1;
#endif
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_elf_info(milist, tid);
#if __arm__
/* 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, at_fault);
#elif __i386__
/* If stack unwinder fails, use the default solution to dump the stack
* content.
*/
stack_depth = unwind_backtrace_with_ptrace_x86(tfd, tid, milist,at_fault);
#else
#error "Unsupported architecture"
#endif
while(milist) {
mapinfo *next = milist->next;
symbol_table_free(milist->symbols);
free(milist);
milist = next;
}
}
#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);
if (ptrace(PTRACE_DETACH, new_tid, 0, 0) != 0) {
XLOG("detach of tid %d failed: %s\n", new_tid, strerror(errno));
need_cleanup = 1;
}
}
closedir(d);
return need_cleanup != 0;
}
/*
* Reads the contents of the specified log device, filters out the entries
* that don't match the specified pid, and writes them to the tombstone file.
*
* If "tailOnly" is set, we only print the last few lines.
*/
static void dump_log_file(int tfd, unsigned pid, const char* filename,
bool tailOnly)
{
bool first = true;
/* circular buffer, for "tailOnly" mode */
const int kShortLogMaxLines = 5;
const int kShortLogLineLen = 256;
char shortLog[kShortLogMaxLines][kShortLogLineLen];
int shortLogCount = 0;
int shortLogNext = 0;
int logfd = open(filename, O_RDONLY | O_NONBLOCK);
if (logfd < 0) {
XLOG("Unable to open %s: %s\n", filename, strerror(errno));
return;
}
union {
unsigned char buf[LOGGER_ENTRY_MAX_LEN + 1];
struct logger_entry entry;
} log_entry;
while (true) {
ssize_t actual = read(logfd, log_entry.buf, LOGGER_ENTRY_MAX_LEN);
if (actual < 0) {
if (errno == EINTR) {
/* interrupted by signal, retry */
continue;
} else if (errno == EAGAIN) {
/* non-blocking EOF; we're done */
break;
} else {
_LOG(tfd, true, "Error while reading log: %s\n",
strerror(errno));
break;
}
} else if (actual == 0) {
_LOG(tfd, true, "Got zero bytes while reading log: %s\n",
strerror(errno));
break;
}
/*
* NOTE: if you XLOG something here, this will spin forever,
* because you will be writing as fast as you're reading. Any
* high-frequency debug diagnostics should just be written to
* the tombstone file.
*/
struct logger_entry* entry = &log_entry.entry;
if (entry->pid != (int32_t) pid) {
/* wrong pid, ignore */
continue;
}
if (first) {
_LOG(tfd, true, "--------- %slog %s\n",
tailOnly ? "tail end of " : "", filename);
first = false;
}
/*
* Msg format is: <priority:1><tag:N>\0<message:N>\0
*
* We want to display it in the same format as "logcat -v threadtime"
* (although in this case the pid is redundant).
*
* TODO: scan for line breaks ('\n') and display each text line
* on a separate line, prefixed with the header, like logcat does.
*/
static const char* kPrioChars = "!.VDIWEFS";
unsigned char prio = entry->msg[0];
char* tag = entry->msg + 1;
char* msg = tag + strlen(tag) + 1;
/* consume any trailing newlines */
char* eatnl = msg + strlen(msg) - 1;
while (eatnl >= msg && *eatnl == '\n') {
*eatnl-- = '\0';
}
char prioChar = (prio < strlen(kPrioChars) ? kPrioChars[prio] : '?');
char timeBuf[32];
time_t sec = (time_t) entry->sec;
struct tm tmBuf;
struct tm* ptm;
ptm = localtime_r(&sec, &tmBuf);
strftime(timeBuf, sizeof(timeBuf), "%m-%d %H:%M:%S", ptm);
if (tailOnly) {
snprintf(shortLog[shortLogNext], kShortLogLineLen,
"%s.%03d %5d %5d %c %-8s: %s",
timeBuf, entry->nsec / 1000000, entry->pid, entry->tid,
prioChar, tag, msg);
shortLogNext = (shortLogNext + 1) % kShortLogMaxLines;
shortLogCount++;
} else {
_LOG(tfd, true, "%s.%03d %5d %5d %c %-8s: %s\n",
timeBuf, entry->nsec / 1000000, entry->pid, entry->tid,
prioChar, tag, msg);
}
}
if (tailOnly) {
int i;
/*
* If we filled the buffer, we want to start at "next", which has
* the oldest entry. If we didn't, we want to start at zero.
*/
if (shortLogCount < kShortLogMaxLines) {
shortLogNext = 0;
} else {
shortLogCount = kShortLogMaxLines; /* cap at window size */
}
for (i = 0; i < shortLogCount; i++) {
_LOG(tfd, true, "%s\n", shortLog[shortLogNext]);
shortLogNext = (shortLogNext + 1) % kShortLogMaxLines;
}
}
close(logfd);
}
/*
* Dumps the logs generated by the specified pid to the tombstone, from both
* "system" and "main" log devices. Ideally we'd interleave the output.
*/
static void dump_logs(int tfd, unsigned pid, bool tailOnly)
{
dump_log_file(tfd, pid, "/dev/log/system", tailOnly);
dump_log_file(tfd, pid, "/dev/log/main", tailOnly);
}
/* 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;
/* don't copy log messages to tombstone unless this is a dev device */
char value[PROPERTY_VALUE_MAX];
property_get("ro.debuggable", value, "0");
bool wantLogs = (value[0] == '1');
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 (wantLogs) {
dump_logs(fd, pid, 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);
}
if (wantLogs) {
dump_logs(fd, pid, false);
}
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 has been suspended while crashing. To\n"
"* attach gdbserver for a gdb connection on port 5039:\n"
"*\n"
"* adb shell gdbserver :5039 --attach %d &\n"
"*\n"
"* Press HOME key to let the process continue crashing.\n"
"********************************************************\n",
cr->pid, cr->pid);
/* wait for HOME key (TODO: something useful for devices w/o 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;
}
snprintf(buf, sizeof buf, "/proc/%d/task/%d", cr.pid, tid);
if(stat(buf, &s)) {
LOG("tid %d does not exist in pid %d. ignoring 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);
/* Note that at this point, the target thread's signal handler
* is blocked in a read() call. This gives us the 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().
*/
tid_attach_status = ptrace(PTRACE_ATTACH, tid, 0, 0);
int ptrace_error = errno;
if (TEMP_FAILURE_RETRY(write(fd, &tid, 1)) != 1) {
XLOG("failed responding to client: %s\n",
strerror(errno));
goto done;
}
if(tid_attach_status < 0) {
LOG("ptrace attach failed: %s\n", strerror(ptrace_error));
goto done;
}
close(fd);
fd = -1;
const int sleep_time_usec = 200000; /* 0.2 seconds */
const int max_total_sleep_usec = 3000000; /* 3 seconds */
int loop_limit = max_total_sleep_usec / sleep_time_usec;
for(;;) {
if (loop_limit-- == 0) {
LOG("timed out waiting for pid=%d tid=%d uid=%d to die\n",
cr.pid, tid, cr.uid);
goto done;
}
n = waitpid(tid, &status, __WALL | WNOHANG);
if (n == 0) {
/* not ready yet */
XLOG("not ready yet\n");
usleep(sleep_time_usec);
continue;
}
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). 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.
*/
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 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);
signal(SIGSTKFLT, SIG_DFL);
signal(SIGPIPE, SIG_DFL);
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);
XLOG("waiting for connection\n");
fd = accept(s, &addr, &alen);
if(fd < 0) {
XLOG("accept failed: %s\n", strerror(errno));
continue;
}
fcntl(fd, F_SETFD, FD_CLOEXEC);
handle_crashing_process(fd);
}
return 0;
}
Reference in a new issue View git blame Copy permalink